please select a Color
please select a Size
Choose a shipping method

Join the co-op today and get back an estimated $15.00 on this item.

Fly over trails in the waterproof, breathable women's REI Co-op Flash hiking boots that are comfy right out of the box. REI-exclusive technologies create fast-and-light boots—with a lighter footprint.

  • Features

    • Strong and socklike FirmaKnit™ uppers are made from 99% recycled PET polyester and are designed for lightweight yet durable comfort right out of the box
    • HydroWall™ complete waterproof/breathable protection keeps your feet dry when the trail ahead isn't—and uses 75% recycled polyester to do so
    • 20% recycled rubber TerraGrip™ tread provides anti-slip grip on all kinds of terrain with 4 mm forefoot climbing lugs for going up and 4 mm heel braking lugs for coming down
    • TerraLoft™ midsoles use 10% algae-based BLOOM™ foam to cradle your feet with a cushioning system that feels like your favorite trail-running shoes (soft, but not too soft)
    • TrailBed™ insoles use Insite® Contoura® technology created with podiatrists to ensure support and comfort; plus, it's made with 25% USDA-certified bio-based Susterra® compound
    • 2-layer 30% recycled TPU overlays are designed to create durable and supportive uppers—the structure you need for long hours on the trail that's still light and minimalist
    • Molded nylon midfoot shanks provide lightweight support to protect your feet from the trail and help propel you forward
    • Recycled PET polyester webbing and lacing creates a midfoot cradle system that allows for a highly adjustable and locked-down fit
    • Extra space in the toe boxes allows for natural changes in your feet (like swelling) during hours of trail exploration
    • Informed by feedback from over 6,000 people and field tested by 100 co-op members over 2,000 hours and 700+ miles


    View all REI Co-op Women's Day Hiking Boots
  • Technical Specs

    Best Use


    Footwear Height


    Footwear Closure




    Type Of Waterproofing

    HydroWall™ waterproof/breathable membrane using 75% recycled polyester


    99% recycled PET polyester FirmaKnit™; 30% recycled thermoplastic urethane (TPU) overlay


    TerraLoft™ EVA using 10% algae-based BLOOM® foam


    Molded nylon midfoot shank


    TerraGrip™ rubber (20% recycled)



    Weight (Pair)

    1 lb. 13 oz.




    Contains recycled materials

  • Size Chart

    6 6.5 7 7.5 8 8.5 9 9.5 10 10.5 11
    U.S. Women's 6 6.5 7 7.5 8 8.5 9 9.5 10 10.5 11
    UK 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5 9
    EU 37 37.5 38 38.5 39 40 40.5 41 42 42.5 43
  • Reviews

    Loading Reviews...
  • Questions & Answers

    Loading Questions...