The women's REI Co-op Flash Air 50 pack is our lightest backpacking pack yet, inspired by thru-hikers across North America and built for those who like to stretch the miles without sacrificing comfort. The UHMWPE ripstop nylon fabric is amazingly durable and allows for a surprisingly long lifespan for such a lightweight pack, while a PFAS-free durable water repellent finish helps moisture bead up on the surface.
A 3D contoured hipbelt and ventilated back panel stay comfortable all day for loads up to 25 lbs. The roll-top lid provides weather resistance and allows compression and adjustment of internal volume, and Packmod compression straps can be run from any loop to any other loop so you can sculpt the pack to the shape of your load. Water bottle pockets are positioned forward on the hipbelt so you don't have to remove the pack to grab your drink, and exterior side pockets, hipbelt pockets and a large front pocket keep frequently needed gear within easy reach.
XS: 24 x 14 x 12 inches, S: 25 x 14 x 12 inches, M: 26 x 14 x 12 inches
Gender
Women's
Sustainability
Contains bluepass certified material, From a Climate Label Certified brand
Highlights
Ultra-high-molecular-weight polyethylene (UHMWPE) fabric is amazingly durable and allows for a surprisingly long lifespan for such a lightweight pack
Durable water repellent (DWR) made without PFAS helps moisture bead up on the surface
3D contoured hipbelt and ventilated back panel are comfortable all day for loads up to 25 lbs.
Roll-top lid provides weather resistance and allows compression and adjustment of internal volume
For a tight load and good balance, Packmod compression straps (included) can be run from any loop to any other loop, so you can sculpt your pack to the shape of your load
Packmod mesh pocket on the shoulder strap is great for phone, snacks, sunglasses and more—or you can take it off altogether to reduce weight
Compatible with Packmod hipbelt lengthener and Rainshield pocket (accessories not included)
Water bottle pockets are positioned forward on the hipbelt so you don't have to remove the pack to grab your drink; cinch closures keep a good grip on slim water bottles
Exterior side pockets and hipbelt pockets are great for storing light items that you want to keep handy
Large front pocket is great for rain shell or other gear you may need to access quickly
Top Y-strap helps you store excess items, including some bear canisters, on exterior of pack
Attachment loops and removable tool keeper allow trekking poles, ice axes and more to be lashed on, expanding your carrying ability while keeping the load stable
Daisy chain with multiple attachment points allows for tailoring exterior loads
Internal hanging loop secures a hydration reservoir (not included); pack design allows tube to be routed over either shoulder
Also comes with a handy mesh pouch (6.3 x 8.7 in.) to store or organize removed Packmod accessory straps or other small items
Contains bluepass certified material
REI Co-op brand is certified to The Climate Label; we actively fund efforts to reduce carbon emissions across our business and support climate projects around the world
Videos
REI Co-op: Better gear is built together. From feedback to field testing, all of our gear is dialed-in by REI Co-op members. Their adventures informed every stitch and detail—making for better, longer-lasting gear.
How to Choose a Backpack?
Capacity: Trip duration is the biggest factor. General guidance: Weekend (1-3 nights): 30-50 liters; Multiday (3-5 nights): 50-80 liters; Extended (5+ nights): 70-plus liters. Features: Consider frame type, storage, padding and ventilation. Fit: Sizing is based on torso length (not height) and hip circumference. Sizing can vary by brand and model, so check a pack's size chart. Finding torso length and hip circumference: Locate your C7 vertebra by tilting your head forward and feeling for the bony bump between your shoulder blades. Place your hands over your hip bones. Draw an imaginary line connecting your thumbs across your lower back. Stand up straight. Have a friend measure from your C7 vertebra to the imaginary line between your thumbs. This is your torso length. To find hip size, measure around the top of your hips, using the same imaginary line you found earlier.
