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Blue Storm
Blue Storm

This product is no longer available.


  • 4-way-stretch polyester fabric wicks moisture off skin and dries fast to prevent you from feeling chilled or clammy; brushed inner surface feels soft and warm
  • The fabric also has a UPF 50+ sun protection rating
  • Space-dye process produces a textured color that's unique to each garment
  • Nonchafing flatseam construction and elastic waistband increase comfort as you move
  • Smooth outer surface slides easily under other layers
  • The men's REI Midweight Long Underwear Bottoms have a functional fly and a next-to-skin fit that hugs the body for optimum performance

Made in USA.

View all REI Men's Long Underwear Bottoms

REI membership


Best Use Snowsports, Hiking
Fabric Polyester
Sun-Protective Fabric Yes
UPF Rating 50
Moisture Wicking Yes
Quick Drying Yes
Underwear Weight Midweight
Inseam (in.) 32 inches
Gender Men's

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100% satisfaction guaranteed

We stand behind everything we sell. If you are not satisfied with your REI purchase, you can return it for a replacement or refund within one year of purchase.

REI's guarantee doesn't cover ordinary wear and tear or damage caused by improper use or accidents.

If your item has a manufacturing defect in its materials or workmanship, you can return it at any time. See our limited warranty.

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At REI, we live and breathe the outdoors, and we're passionate about sharing our expertise with people of all skill levels. Whether you're new to the outdoors or a seasoned explorer, we'll take the time to understand your needs and help you find the right gear for you.

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Anyone can shop at REI, but for a one-time $20 fee you can become an REI member and enjoy a lifetime of benefits. These include an annual member refund, typically 10% back on eligible purchases.*



*10% is typical but not guaranteed. Your refund is based on eligible purchases, which exclude REI gift cards, services, fees, REI Adventures trips, REI Garage, and discounted items. Learn more