Comfort & Support
Organization
Weight
Durability
Water Resistance
Sustainability
Weight
1 lb. 4.8 oz.
Capacity
20L (30, 40L)
Hipbelt
Webbing
Suspension
Frameless
Pros
Cons
Ultimate Direction Fastpack 20
The Ultimate Direction Fastpack 20 blends the fit of a running vest with the storage of a hiking daypack, delivering a snug, body-hugging feel ideal for fast-moving adventures. Its vest-style harness uses dual chest buckles for secure, bounce-free support, and the thin webbing hipbelt and flexible shoulder straps conform well without adding bulk. There’s not much padding, but I found that to be a benefit when moving fast—it keeps the pack light and close to the body without chafing.
I carried 15 to 20 pounds of gear on multiple outings, including food, water, and climbing equipment, and the pack handled the load surprisingly well. The soft foam backpanel was unobtrusive, even when the pack was fully loaded. However, the pack lacks a frame or stays, so comfort does start to break down with heavier setups. Overloading it causes the pack to sag and pull on the shoulders more than I’d like. For heavier hiking loads, a pack like the Osprey Talon Velocity offers better load support while still retaining a vest-inspired shape.
Ultimately, the Fastpack 20 is purpose-built for fastpacking, long-distance trail running, and hybrid hike/run outings. Its streamlined design and light carry make it perfect for covering big miles efficiently, but it’s less suited for slower-paced hikes with substantial gear. The ability to use it as both a travel bag and a performance pack adds to its versatility, especially for those planning multi-sport days or light overnight pushes.
The UD Fastpack 20 strikes a solid balance between streamlined storage and trail-ready utility. Its main compartment is spacious enough for layers, food, and gear, with both top and side zip access for easy packing and retrieval. Inside, a small zippered pouch is ideal for valuables or toiletries. While it doesn’t include soft flasks, the vest-style harness features two cinch-style front pockets that work perfectly with standard soft bottles for on-the-go hydration with minimal bounce.
Additional storage includes dual side pockets that easily fit standard Nalgene bottles, a large external stretch pocket for quick-access layers like a rain shell, and several small front stash pockets for snacks, chapstick, or a phone—one of which zips shut for secure access. There’s also a hydration bladder sleeve in the main compartment, though I preferred using soft flasks up front.
In terms of layout, it’s a hybrid between a running vest and a traditional daypack—more technical than something like the Osprey Daylite, but with far more capacity than a standard running vest. It works especially well for fastpacking or mixed run/hike days where gear volume matters. My one gripe: a pair of front pockets feature internal dividers that seem well-intentioned but ended up too tight to be practical—I struggled to fit much more than a gel or two inside, and accessing items was awkward.
At 1 pound 4.8 ounces, the Fastpack 20 is impressively light for a pack with this much storage and functionality. It undercuts most traditional hiking daypacks—like the Gregory Miko or Osprey Talon—which typically land over 2 pounds. That weight savings makes a real difference on long days when speed and efficiency matter. For an even lighter alternative, the Black Diamond Distance 22 trims down to 14.9 ounces, but its focused, stripped-back design is best for mountain running and scrambling (for more, read our BD Distance 22 review). The Mystery Ranch Gallagator (1 lb. 6.4 oz.) comes close in weight but falls behind in both comfort and organization.
Despite its low weight, the Fastpack 20 is surprisingly versatile. It’s suitable for trail running, long hikes, travel, or even minimalist overnights. While it’s not the kind of pack you’d throw into a larger backpacking pack (even though you could remove the back pad), it’s clearly designed to be worn—not carried—and excels when used for its intended purpose: moving fast with functional gear capacity.
The Ultimate Direction Fastpack 20 is built with lightweight polyester fabric—there’s no listed denier, but the material feels thin and clearly prioritizes minimalism over ruggedness. This isn’t a pack meant for rough terrain or heavy abuse. That said, I owned an earlier version of this pack, and it held up well over years of consistent use. The main weak point in my experience was the plastic buckles—one broke after extended wear, though it was easy to replace.
Otherwise, the construction is fair for the weight. The zippers—often the first thing to fail on lightweight packs—performed reliably, even when exposed to dirt and trail grit. At $150, it’s a decent value for a niche product that, with proper care, should last several seasons of trail use. Still, this is not the pack to choose if you prioritize durability. Options like the Osprey Talon (100D nylon) or Stratos (210D nylon) offer far more robust builds, though they weigh significantly more and serve different purposes. The Fastpack is best seen as a specialized tool: light, capable, and efficient—but not indestructible.
The Fastpack 20 doesn’t include a rain cover—a notable omission for a pack at this price point. The thin polyester fabric absorbs moisture quickly, and the vest-style harness material on the front soaks through just as easily. If you plan to use this pack in wet conditions, a separate rain cover is a smart (and likely necessary) investment. Something like REI’s Duck’s Back cover will run you around $25–$35. Without added protection, the pack can become saturated and heavy, and your gear may be at risk. For dry-weather use, it’s of course completely fine—but don’t count on built-in water resistance.
Select icon to view details:
Longevity
Choosing durable outdoor gear is perhaps the most effective way to reduce environmental impact—the longer it lasts, the less it needs to be produced. Our proprietary longevity rating evaluates overall build quality based on factors such as materials, fabric denier, component durability (including zippers and toggles), real-world performance as reported by our field testers, and our experiences with the brand.
PFAS-Free DWR
This product’s DWR (Durable Water Repellent) finish is made without per- and polyfluoroalkyl substances (PFAS). These synthetic compounds are known as "forever chemicals” because they take an extremely long time to degrade, if at all. PFAS can eventually end up in everything from soil to drinking water and have been linked to a range of health issues.
Recycled Materials
This product is made partly or entirely from recycled materials, the most common being nylon, polyester, wool, and down. Some products include a single recycled component or partially recycled fabric, while others are 100% recycled (generally excluding accessories like zippers, Velcro, toggles, etc). Look for these details in our product sustainability report linked below.
Bluesign Approved
Bluesign Technologies, based in Switzerland, is a third-party textile certification system that ensures materials are manufactured to strict environmental and worker safety standards. A Bluesign-approval denotes that some of the product’s materials have gone through a rigorous vetting process. A Bluesign Product goes the next mile: These contain more than 90% Bluesign-approved fabrics and more than 20% Bluesign-approved accessories.
Responsible Manufacturing
This criterion evaluates this brand's commitment to fair wages, safe working conditions, and reducing its environmental impact throughout the production process. Responsible manufacturing is most commonly demonstrated through certifications and membership in programs such as Fair Trade Certified, Fair Wear Foundation, Worldwide Responsible Accreditation of Production, and the Fair Labor Association. We also recognize brands that prioritize local production, such as those that manufacture primarily in the United States or Europe, to reduce carbon emissions, maintain better oversight of working conditions, and comply with strict social and environmental regulations.
Recycled and/or Reduced Packaging
This brand uses recycled packaging and/or is making efforts to reduce packaging altogether. For example, it may use a certain percentage of recycled cardboard or make efforts to use less plastic across its packaging operation. In some cases, brands also use Forest Stewardship Council-certified paper products, which helps to ensure sustainable sourcing of forest materials.
Repair Services
This brand offers repair services, which can extend this product's lifespan and reduce overall consumption. Some brands offer comprehensive repair programs that can fix a wide range of issues, while others have more limited capabilities. If a brand's warranty policy only covers replacement, rather than repair, these programs usually do not meet this criterion.
Resale and/or Recycling Services
This brand has a resale and/or recycling program, which helps keep gear in circulation for longer and out of landfills. The most common form is a trade-in program, where consumers can exchange items for store credit, which is then resold. Some brands accept products back for recycling at the end of their life, thereby reducing waste. Occasionally, some do both.
Carbon Footprint Tracking
This criterion evaluates whether this brand measures its greenhouse gas emissions, along with its commitment to reduction and transparency in reporting. Typically, we require brands to follow established frameworks such as the Higg Index, Greenhouse Gas Protocol, or The Change Climate Project. Generally, companies use the widely recognized scope categorization system for measuring brand emissions.
Annual Impact Report
This brand produces and publishes an annual impact report for public consumption, tracking its environmental footprint and sustainability efforts. These reports vary in form but generally cover topics such as material sourcing, greenhouse gas and emissions tracking, waste and water usage, supply chain analysis, and packaging efforts. An impact report is an important step toward transparency and accountability on the sustainability front.
The Ultimate Direction Fastpack 20 is offered in two sizes, with fit based on torso length and chest circumference. I went with the Small/Medium based on the size chart, and it fit true to size. The pack rides high and close to the body—an ideal setup for running, where stability and reduced bounce matter most. I found the fit comfortable and secure, with plenty of adjustability through the chest and hip straps to fine-tune as needed.
The webbing hipbelt sits below the dual chest buckles and can be removed or left unbuckled, depending on your preference. I found myself skipping it entirely on casual outings, which didn’t impact comfort or pack stability for lighter loads.
Black Diamond Distance 22 ($200): For Mountain-Minded Fastpackers
At a glance, the Distance 22 and Fastpack 20 look nearly identical—both pair a running vest-style harness with a streamlined backpack. If you want a daypack that moves with you and provides quick access to food and snacks, either is a solid choice. But the Distance is fine-tuned for running and scrambling, centering its weight higher on the shoulder blades for a bounce-free ride—so long as you don’t overload it. It also boasts a sturdier shell fabric and more functional front pocket organization. That said, the Fastpack offers a slightly larger capacity, a more refined fit, and better comfort with heavier loads, all while saving you $50. For more, read our BD Distance 22 review.
Mystery Ranch Gallagator 20 ($109): Speed on a Budget
Running vest-style daypacks tend to be pricey, but the Gallagator undercuts even the already affordable Fastpack. It’s slightly lighter, though its design—particularly the chest harness—feels less refined. Mystery Ranch’s trademark triple-zipper main compartment isn’t as intuitive as the Fastpack’s side-access zipper, and the Gallagator has a bulkier feel overall. That said, it still gets the job done if you’re looking for a vest-style daypack with moderate storage, and its price tag is hard to ignore. While it falls short of the Fastpack in organization and comfort, it’s still a solid budget-friendly alternative. For a deeper dive, see our review of the Gallagator 25.
Despite the Fastpack 20’s specialized look, this pack can do almost anything. Add in its extremely reasonable price point, and you get one of our favorite overall models in this review. It does have some storage foibles, though.
Comfort & Support
Organization
Weight
Durability
Water Resistance
Sustainability
The Distance wants to turn you into a mountain-eating speed demon. This light pack has storage for every gel packet and wicking layer you possess, and its beefy running vest-style harness hugs it close to your body on scrambles and trail runs. Make sure not to overload what little support it offers, though.
Comfort & Support
Organization
Weight
Durability
Water Resistance
Sustainability
This fast-and-light pack has a busy aesthetic, with ample storage for technical missions and casual outings alike. The Gallagator 25 is also priced very competitively, although we think there are better running-oriented packs on the market.
Comfort & Support
Organization
Weight
Durability
Water Resistance
Sustainability
If you’re looking for a lightweight, vest-style pack that bridges the gap between a running vest and a hiking daypack, the Ultimate Direction Fastpack 20 is a strong choice. For those who like to move quickly on the trail—mixing running, hiking, and scrambling—its low weight, snug fit, and on-the-go storage make a compelling case. It’s certainly not the best option for hauling heavy loads or enduring rugged abuse, but for fast-moving days with a streamlined kit, the Fastpack 20 has real appeal.
dial your trail kit
Gear Guide
Best Hiking Daypacks of 2025Gear Guide
Best Hiking Pants of 2025Gear Guide
Best Hiking Shoes of 2025Gear Guide
Best Trekking Poles of 2025Gear Guide
Best Hiking Boots of 2025