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Long Sleeve Base Layers
(234 products)Products (234)
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- SmartwoolClassic Thermal Merino Lettuce Edge Crew Base Layer Top - Women's$82.73Save 28%compared to  $115.00Members use code LABORDAY2025 for an extra 20% off at REI OutletUnderwear Weight:MidweightSize Type:RegularREI OUTLET
- SpraywayEffra Jacket Base Layer Top - Women's$42.73Save 34%compared to  $64.95Members use code LABORDAY2025 for an extra 20% off at REI OutletUnderwear Weight:HeavyweightSize Type:RegularREI OUTLET
- IcebreakerMerino 260 Tech Long-Sleeve Half-Zip Thermal Base Layer Top - Women'sTop Rated$99.73Save 26%compared to  $135.00Members use code LABORDAY2025 for an extra 20% off at REI OutletUnderwear Weight:HeavyweightSize Type:Regular, PlusREI OUTLET
- SmartwoolClassic Thermal Merino Base Layer Quarter-Zip - Kids'$51.73Save 26%compared to  $70.00Members use code LABORDAY2025 for an extra 20% off at REI OutletUnderwear Weight:MidweightSize Type:RegularREI OUTLET
- SmartwoolClassic All-Season Merino Quarter-Zip Base Layer Top - Women's$95.00Size Type:Regular
- PatagoniaCapilene Thermal Weight Zip-Neck Long Underwear Top - Women's$109.00Underwear Weight:HeavyweightSize Type:Regular
- Helly HansenHH LIFA Base Layer Set - Kids'$70.00Underwear Weight:UltralightweightSize Type:Regular
- Black DiamondSolution 150 Merino Base Layer Crew Top - Women'sTop Rated$99.73Save 26%compared to  $135.00Members use code LABORDAY2025 for an extra 20% off at REI OutletUnderwear Weight:LightweightSize Type:RegularREI OUTLET
- CraftCORE Dry Active Comfort Base Layer Top - Women's$39.73Save 38%compared to  $64.95Members use code LABORDAY2025 for an extra 20% off at REI OutletUnderwear Weight:MidweightSize Type:RegularREI OUTLET
- IcebreakerMerino 200 Oasis Long-Sleeve Crewe Thermal Top - Women'sTop Rated$49.83 - $105.00Underwear Weight:MidweightSize Type:Regular, Plus
- PatagoniaCapilene Midweight Zip-Neck Base Layer Top - Women's$99.00Underwear Weight:MidweightSize Type:Regular
- PatagoniaCapilene Thermal Weight Long Underwear Crew Top - Women's$99.00Underwear Weight:HeavyweightSize Type:Regular
- SmartwoolClassic Thermal Merino Base Layer Crew One-Piece - Women'sNew arrival$250.00Underwear Weight:MidweightSize Type:Regular
- SmartwoolIntraknit Thermal Merino Pattern Crew Base Layer Top - Women's$96.73Save 25%compared to  $130.00Members use code LABORDAY2025 for an extra 20% off at REI OutletUnderwear Weight:MidweightSize Type:RegularREI OUTLET
- Terramar2.0 Cloud Nine Midweight Performance Base Layer Scoop Shirt - Women's$29.73Save 33%compared to  $45.00Members use code LABORDAY2025 for an extra 20% off at REI OutletUnderwear Weight:MidweightSize Type:RegularREI OUTLET
- SpraywayEffra Hoody Base Layer Top - Women's$49.73Save 28%compared to  $69.95Members use code LABORDAY2025 for an extra 20% off at REI OutletUnderwear Weight:HeavyweightSize Type:Regular, PlusREI OUTLET
- The North FaceFD Pro 160 Base Layer Crew Top - Women's$70.00Underwear Weight:MidweightSize Type:Regular
- SeirusHeatwave All Season Reversible Long-Sleeve Base Layer Top - Women's$36.83Save 50%compared to  $75.00Underwear Weight:LightweightSize Type:Regular
- Terramar2.0 Cloud Nine Midweight Performance Thermal Turtleneck - Women's$32.73Save 31%compared to  $48.00Members use code LABORDAY2025 for an extra 20% off at REI OutletUnderwear Weight:MidweightSize Type:RegularREI OUTLET
- Arc'teryxRho Hoody Base Layer Top - Women'sTop Rated$140.00Underwear Weight:LightweightSize Type:Regular
- Helly HansenMerino Wool Base Layer Set - Kids'$75.73Save 36%compared to  $120.00Members use code LABORDAY2025 for an extra 20% off at REI OutletUnderwear Weight:LightweightSize Type:RegularREI OUTLET
- Arms of Andes300 Lightweight Alpaca Wool Pullover Base Layer Hoodie - Women's$140.00Underwear Weight:LightweightSize Type:Regular
- HalfdaysJohnson Base Layer Top - Women's$49.83Save 41%compared to  $85.00Underwear Weight:UltralightweightSize Type:Plus
- ArtilectFlatiron 185 Quarter-Zip Base Layer Top - Women's$99.73Save 37%compared to  $160.00Members use code LABORDAY2025 for an extra 20% off at REI OutletUnderwear Weight:MidweightSize Type:RegularREI OUTLET
- ArtilectDarkhorse 185 Zoned Quarter-Zip Base Layer Top - Women's$116.73Save 31%compared to  $170.00Members use code LABORDAY2025 for an extra 20% off at REI OutletUnderwear Weight:MidweightSize Type:RegularREI OUTLET
- Helly HansenGraphic Lifa Merino Base Layer Set - Kids'$74.73Save 32%compared to  $110.00Members use code LABORDAY2025 for an extra 20% off at REI OutletUnderwear Weight:HeavyweightSize Type:RegularREI OUTLET
- SmartwoolIntraknit Thermal Merino Crew Base Layer Top - Women's$130.00Underwear Weight:MidweightSize Type:Regular
- Helly HansenLIFA Merino Midweight 2-In-1 Graphic Half-Zip Base Layer Top - Women's$86.73Save 27%compared to  $120.00Members use code LABORDAY2025 for an extra 20% off at REI OutletUnderwear Weight:MidweightSize Type:RegularREI OUTLET
- SmartwoolClassic Thermal Merino Base Layer Hoodie - Kids'$51.73Save 31%compared to  $75.00Members use code LABORDAY2025 for an extra 20% off at REI OutletUnderwear Weight:MidweightSize Type:RegularREI OUTLET
- Helly HansenLIFA ACTIVE Graphic Crew Base Layer Top - Women's$42.73Save 34%compared to  $65.00Members use code LABORDAY2025 for an extra 20% off at REI OutletUnderwear Weight:LightweightSize Type:RegularREI OUTLET
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