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  • Polartec Power Dry uses 2 different yarns on either side of the fabric to enhance comfort: interior yarn wicks moisture, and exterior yarn dries quickly
  • The combination of the 2 yarns helps keep you dry during highly aerobic activities because it moves moisture away from skin faster than single-component fabrics such as cotton
  • Fabric protects skin against harmful ultraviolet light with a UPF rating of 20 and is very soft to the touch
  • Deep center front zipper allows ventilation control; features an inner draft flap and locking zipper head
  • Flatseam construction is soft and non-chafing next to skin; raglan sleeves with off-the-shoulder seams minimize irritation when wearing a pack
  • Underarm and side gussets promote freedom of motion
  • Dropped back hem stays tucked in
  • The REI Lightweight Polartec Power Dry Half-Zip top for men features a next-to-skin fit that hugs the body and boosts fabric performance

Made in USA.

View all REI Men's Long Underwear Tops

REI membership


Best Use Multisport
Shirt Style Zip-front
Fabric Polartec Power Dry polyester
Sun-Protective Fabric Yes
Moisture Wicking Yes
Quick Drying Yes
Underwear Weight Lightweight
Sleeve Length Long Sleeve
Gender Men's

Size chart

Sizing notes

SHORT: Some pants are available in short sizes, which generally means an inseam that is 2.5 inches shorter than regular sizes. TALL: Some pants, shirts, jackets and parkas are available in tall sizes, which generally means an inseam that is 3 inches longer and a rise that is 1 inch longer, a shirt or jacket body that is 2 inches longer, a parka body that is 2.5 inches longer and sleeves that are 2.5 inches longer than regular sizes.