REI Co-op Flash Hiking Boots - Kids'

Color: Apex Yellow
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Members get an estimated $7.00 (10%) back on this item as a part of your annual .

Members get an estimated $7.00 (10%) back on this item.
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Watch them fly over trails in the waterproof/breathable REI Co-op Flash kids' hiking boots. REI-exclusive technologies create fast-and-light boots—with a lighter footprint and comfy that won't quit.


  • Strong and socklike FirmaKnit™ uppers are made from 99% recycled PET polyester, and they're designed for lightweight yet durable comfort right out of the box
  • HydroWall™ complete waterproof/breathable protection keeps their 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 their feet with a cushioning system that feels like their 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 they need for long hours on the trail that's still light and minimalist
  • Molded nylon midfoot shanks provide lightweight support to protect their feet from the trail and help propel them 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 their 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 the REI Co-op Flash Product LineView all REI Co-op Kids' 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 lbs. 14 oz.




Contains recycled materials

From a Climate Neutral Certified brand

Size Chart

1 Kids2 Kids3 Kids4 Kids5 Kids6 Kids
Foot Length (in.)7.8758.258.6258.8759.259.625

15 reviews with an average rating of 3.7 out of 5 stars

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