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(563 products)
Products (563)
Sort: Best Match
    Top Rated
    IcebreakerMerino 200 Oasis Long-Sleeve Base Layer Crew Top - Kids'
    $41.93
    Save 30%
    compared to  $60.00
    8 reviews with an average rating of 4.5 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular
    SmartwoolIntraknit Thermal Merino Base Layer Bottoms - Men's
    $130.00
    23 reviews with an average rating of 4.3 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Big
    SmartwoolClassic Thermal Merino Base Layer Bottoms - Women's Plus Sizes
    $115.00 - $120.00
    19 reviews with an average rating of 4.4 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Plus
    Terramar3.0 Thermawool Base Layer Tights - Women's
    $52.73
    Save 24%
    compared to  $70.00
    Members use code LABORDAY2025 for an extra 20% off at REI Outlet
    2 reviews with an average rating of 1.5 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular
    REI OUTLET
    New arrival
    SmartwoolClassic Thermal Merino Base Layer Crew One-Piece - Men's
    $250.00
    0 reviews
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Big
    Kari TraaLucie Base Layer Pants - Women's
    $58.73
    Save 26%
    compared to  $80.00
    Members use code LABORDAY2025 for an extra 20% off at REI Outlet
    1 reviews with an average rating of 5.0 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
    REI OUTLET
    Top Rated
    Icebreaker260 ZoneKnit Base Layer Leggings - Men's
    $119.73
    Save 27%
    compared to  $165.00
    Members use code LABORDAY2025 for an extra 20% off at REI Outlet
    9 reviews with an average rating of 4.8 out of 5 stars
    Underwear Weight:
    Heavyweight
    Size Type:
    Big
    REI OUTLET
    Icebreaker125 ZoneKnit Merino Thermal Leggings - Men's
    $93.73
    Save 25%
    compared to  $125.00
    Members use code LABORDAY2025 for an extra 20% off at REI Outlet
    1 reviews with an average rating of 5.0 out of 5 stars
    Underwear Weight:
    Ultralightweight
    Size Type:
    Regular, Big
    REI OUTLET
    StanceAlonzo Boxer Briefs - Men's
    $19.73
    Save 26%
    compared to  $27.00
    Members use code LABORDAY2025 for an extra 20% off at REI Outlet
    0 reviews
    Size Type:
    Regular
    REI OUTLET
  • Sale Ends Aug 28
    Top Rated
    ArtilectDarkhorse 185 Zoned Crew Base Layer Top - Men's
    $79.99
    Save 50%
    compared to  $160.00
    Members use code LABORDAY2025 for an extra 20% off at REI Outlet
    7 reviews with an average rating of 4.6 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular
    REI OUTLET
  • Sale Ends Aug 28
    StancePalmer Boxer Briefs - Men's
    $12.49
    Save 50%
    compared to  $25.00
    Members use code LABORDAY2025 for an extra 20% off at REI Outlet
    0 reviews
    Size Type:
    Regular, Big
    REI OUTLET
    Helly HansenLIFA Merino Midweight Graphic Base Layer Pants - Women's
    $79.73
    Save 27%
    compared to  $110.00
    Members use code LABORDAY2025 for an extra 20% off at REI Outlet
    1 reviews with an average rating of 1.0 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular
    REI OUTLET
    SmartwoolClassic Thermal Merino Colorblock Crew Base Layer Top - Men's
    $130.00
    1 reviews with an average rating of 5.0 out of 5 stars
    Size Type:
    Regular, Big
    Top Rated
    IcebreakerMerino 260 Tech Thermal Base Layer Leggings With Fly - Men's
    $93.73
    Save 25%
    compared to  $125.00
    Members use code LABORDAY2025 for an extra 20% off at REI Outlet
    37 reviews with an average rating of 4.8 out of 5 stars
    Underwear Weight:
    Heavyweight
    Size Type:
    Regular, Big
    REI OUTLET
    IcebreakerMerino 260 Tech Long-Sleeve Half-Zip Thermal Base Layer Top - Kids'
    $52.73
    Save 29%
    compared to  $75.00
    Members use code LABORDAY2025 for an extra 20% off at REI Outlet
    4 reviews with an average rating of 4.5 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular
    REI OUTLET
    Arms of Andes160 Ultralight Alpaca Wool Long-Sleeve Base Layer Shirt - Women's
    $85.00 - $100.00
    11 reviews with an average rating of 3.8 out of 5 stars
    Underwear Weight:
    Ultralightweight
    Size Type:
    Regular
    Helly HansenLIFA Merino Midweight 2-In-1 Base Layer Hoodie - Women's
    $86.73
    Save 27%
    compared to  $120.00
    Members use code LABORDAY2025 for an extra 20% off at REI Outlet
    0 reviews
    Underwear Weight:
    Midweight
    Size Type:
    Regular
    REI OUTLET
    SmartwoolIntraknit Thermal Merino Crew Base Layer Top - Men's
    $92.73
    Save 28%
    compared to  $130.00
    Members use code LABORDAY2025 for an extra 20% off at REI Outlet
    9 reviews with an average rating of 4.1 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Big
    REI OUTLET
    Helly HansenLifa Merino Midweight Base Layer Pants - Men's
    $100.00 - $105.00
    1 reviews with an average rating of 5.0 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Big
    SaxxDropTemp Cooling Mesh Boxer Briefs - Men's
    $38.00
    41 reviews with an average rating of 3.8 out of 5 stars
    Size Type:
    Regular
    IcebreakerMerino 200 Oasis Base Layer Leggings - Kids'
    $41.93
    Save 30%
    compared to  $60.00
    6 reviews with an average rating of 3.8 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
    RONHILLBrief Underwear - Women's
    $19.73
    Save 34%
    compared to  $29.95
    Members use code LABORDAY2025 for an extra 20% off at REI Outlet
    1 reviews with an average rating of 4.0 out of 5 stars
    Size Type:
    Regular
    REI OUTLET
    IcebreakerMerino 200 Oasis Long-Sleeve Crewe Macro Forms Base Layer Top - Women's
    $85.73
    Save 25%
    compared to  $115.00
    Members use code LABORDAY2025 for an extra 20% off at REI Outlet
    3 reviews with an average rating of 3.7 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular
    REI OUTLET
    StanceInvestor Boxer Briefs - Men's
    $20.73
    Save 30%
    compared to  $30.00
    Members use code LABORDAY2025 for an extra 20% off at REI Outlet
    3 reviews with an average rating of 4.7 out of 5 stars
    Size Type:
    Regular
    REI OUTLET
    Top Rated
    SmartwoolClassic Thermal Merino Crew Base Layer Top - Kids'
    $35.93 - $65.00
    80 reviews with an average rating of 4.8 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular
    Icebreaker125 ZoneKnit Crewe Base Layer Shirt - Women's
    $84.73
    Save 26%
    compared to  $115.00
    Members use code LABORDAY2025 for an extra 20% off at REI Outlet
    0 reviews
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
    REI OUTLET
    Ortovox230 Competition Long-Sleeve Base Layer Top - Men's
    $110.00
    2 reviews with an average rating of 3.5 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Big
    Helly HansenHH LIFA ACTIVE Base Layer Set - Kids'
    $54.73
    Save 31%
    compared to  $80.00
    Members use code LABORDAY2025 for an extra 20% off at REI Outlet
    0 reviews
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
    REI OUTLET
    Top Rated
    Icebreaker200 Oasis Long-Sleeve Half-Zip Base Layer Top - Men's
    $115.00
    17 reviews with an average rating of 4.8 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Big
    Top Rated
    Outdoor ResearchAlpine Onset Merino 150 Base Layer Hoodie - Women's
    $119.00
    7 reviews with an average rating of 5.0 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Plus
Sort: Best Match

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