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Base Layers

(343 products)
Products (343)
Sort: Best Match
    REI Co-opMidweight Base Layer Bottoms - Men's
    $54.95
    101 reviews with an average rating of 4.5 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Big, Tall
    REI Co-opHeavyweight Merino Long-Sleeve Base Layer Crew Top - Men's
    $69.93 - $99.95
    41 reviews with an average rating of 4.4 out of 5 stars
    Underwear Weight:
    Heavyweight
    Size Type:
    Regular, Big, Tall
    Top Rated
    REI Co-opMidweight Long-Sleeve Base Layer Top - Men's
    $37.93 - $54.95
    198 reviews with an average rating of 4.6 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Big, Tall
    Top Rated
    SmartwoolClassic Thermal Merino Quarter-Zip Base Layer Top - Women's
    $130.00
    56 reviews with an average rating of 4.8 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Plus
    Top Rated
    SmartwoolClassic Thermal Merino Base Layer Bottoms - Men's
    $125.00
    640 reviews with an average rating of 4.7 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Big
    Top Rated
    SmartwoolClassic Thermal Merino Quarter-Zip Base Layer Top - Men's
    $130.00
    51 reviews with an average rating of 4.7 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Big
    Top Rated
    SmartwoolClassic Thermal Merino Crew Base Layer Top - Men's
    $125.00
    1513 reviews with an average rating of 4.7 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Big
    Top Rated
    SmartwoolClassic Thermal Merino Crew Base Layer Top - Women's
    $125.00
    1213 reviews with an average rating of 4.7 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Plus
    SmartwoolClassic Thermal Merino Base Layer Bottoms - Women's
    $125.00
    761 reviews with an average rating of 4.4 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular
    Top Rated
    REI Co-opHeavyweight Merino Base Layer Half-Zip Top - Women's
    $72.93 - $104.95
    29 reviews with an average rating of 4.7 out of 5 stars
    Underwear Weight:
    Heavyweight
    Size Type:
    Regular, Plus
    REI Co-opHeavyweight Merino Base Layer Bottoms - Women's
    $69.93 - $99.95
    33 reviews with an average rating of 4.4 out of 5 stars
    Underwear Weight:
    Heavyweight
    Size Type:
    Regular, Plus
    REI Co-opMidweight Base Layer Tights - Women's
    $54.95
    124 reviews with an average rating of 4.3 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Plus, Petite
    Top Rated
    REI Co-opMidweight Base Layer Half-Zip Top - Men's
    $41.93 - $59.95
    182 reviews with an average rating of 4.6 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Big, Tall
    REI Co-opMidweight Long-Sleeve Base Layer Top - Women's
    $54.95
    319 reviews with an average rating of 4.2 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Plus
    Top Rated
    REI Co-opHeavyweight Merino Base Layer Bottoms - Men's
    $69.93 - $99.95
    18 reviews with an average rating of 4.8 out of 5 stars
    Underwear Weight:
    Heavyweight
    Size Type:
    Regular, Big, Tall
    Top Rated
    SmartwoolClassic All-Season Merino Long-Sleeve Base Layer Top - Men's
    $66.93 - $100.00
    87 reviews with an average rating of 4.6 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Big
    REI Co-opHeavyweight Merino Long-Sleeve Base Layer Crew Top - Women's
    $69.93 - $99.95
    44 reviews with an average rating of 4.4 out of 5 stars
    Underwear Weight:
    Heavyweight
    Size Type:
    Regular, Plus
    SmartwoolClassic All-Season Merino Long-Sleeve Base Layer Top - Women's
    $100.00
    134 reviews with an average rating of 4.4 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Plus
    Top Rated
    REI Co-opLightweight Long-Sleeve Crew Base Layer Top - Women's
    $44.95
    31 reviews with an average rating of 4.6 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Plus
    Top Rated
    PatagoniaCapilene Midweight Crew Base Layer Top - Women's
    $49.83 - $89.00
    51 reviews with an average rating of 4.6 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Plus
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    REI Co-opMerino 185 Base Layer Bottoms - Men's
    $79.95
    161 reviews with an average rating of 4.2 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Big
    REI Co-opMerino 185 Base Layer Bottoms - Women's
    $79.95
    121 reviews with an average rating of 4.2 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
    Top Rated
    PatagoniaCapilene Midweight Crew Base Layer Top - Men's
    $61.93 - $89.00
    89 reviews with an average rating of 4.5 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Big
    Top Rated
    REI Co-opMidweight Base Layer Bottoms - Kids'
    $34.95
    14 reviews with an average rating of 4.7 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular
    Top Rated
    REI Co-opMerino 185 Long-Sleeve Half-Zip Base Layer Top - Men's
    $62.93 - $89.95
    124 reviews with an average rating of 4.5 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Big
    tasc PerformanceElevation Merino T-Shirt - Women's
    $54.73
    Save 30%
    compared to  $79.00
    93 reviews with an average rating of 4.3 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Plus
    REI OUTLET
    Top Rated
    REI Co-opMidweight Base Layer Crew Top - Kids'
    $34.95
    8 reviews with an average rating of 4.9 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular
    Top Rated
    REI Co-opMerino 185 Long-Sleeve Base Layer Top - Men's
    $79.95
    221 reviews with an average rating of 4.5 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Big
    Top Rated
    REI Co-opLightweight Crew Base Layer Top - Men's
    $34.95
    26 reviews with an average rating of 4.6 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Big, Tall
    Top Rated
    REI Co-opMerino Midweight Base Layer Crew Top - Kids'
    $36.93
    Save 26%
    compared to  $49.95
    32 reviews with an average rating of 4.8 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular
1–30 of 343 products
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