Polyester Base Layers
(96 products)- REI Co-opMidweight Base Layer Bottoms - Men's$54.95Underwear Weight:MidweightSize Type:Regular, Big, Tall
- REI Co-opMidweight Long-Sleeve Base Layer Top - Women's$54.95Underwear Weight:MidweightSize Type:Regular, Plus
- REI Co-opMidweight Long-Sleeve Base Layer Top - Men'sTop Rated$37.93 - $54.95Underwear Weight:MidweightSize Type:Regular, Big, Tall
- REI Co-opMidweight Base Layer Tights - Women's$54.95Underwear Weight:MidweightSize Type:Regular, Plus, Petite
- REI Co-opMidweight Base Layer Half-Zip Top - Men'sTop Rated$41.93 - $59.95Underwear Weight:MidweightSize Type:Regular, Big, Tall
- PatagoniaCapilene Midweight Crew Base Layer Top - Men'sTop Rated$61.93 - $89.00Underwear Weight:MidweightSize Type:Regular, Big
- REI Co-opMidweight Base Layer Half-Zip Top - Women's$59.95Underwear Weight:MidweightSize Type:Regular, Plus
- REI Co-opMidweight Base Layer Crew Top - Kids'Top Rated$34.95Underwear Weight:MidweightSize Type:Regular
- Arc'teryxRho Base Layer Bottoms - Women's$24.83 - $100.00Underwear Weight:LightweightSize Type:Regular, Plus
- REI Co-opMidweight Base Layer Bottoms - Kids'Top Rated$34.95Underwear Weight:MidweightSize Type:Regular
- Arc'teryxRho LT Zip-Neck Base Layer Top - Men's$120.00Underwear Weight:LightweightSize Type:Regular, Big
- REI Co-opLightweight Long-Sleeve Crew Base Layer Top - Men's$44.95Underwear Weight:LightweightSize Type:Regular, Big, Tall
- REI Co-opLightweight Base Layer Bottoms - Men'sTop Rated$44.95Underwear Weight:LightweightSize Type:Regular, Big, Tall
- PatagoniaCapilene Midweight Base Layer Bottoms - Men'sTop Rated$89.00Underwear Weight:MidweightSize Type:Regular, Big
- REI Co-opLightweight Long-Sleeve Crew Base Layer Top - Women'sTop Rated$44.95Underwear Weight:LightweightSize Type:Regular, Plus
- Arc'teryxRho LT Crew Neck Base Layer Top - Men'sTop Rated$100.00Underwear Weight:LightweightSize Type:Regular, Big
- PatagoniaCapilene Midweight Zip-Neck Base Layer Top - Men's$68.93 - $99.00Underwear Weight:MidweightSize Type:Regular, Big
- PatagoniaCapilene Midweight Crew Base Layer Top - Women'sTop Rated$49.83 - $89.00Underwear Weight:MidweightSize Type:Regular, Plus
- PatagoniaCapilene Midweight Base Layer Bottoms - Women's$61.93 - $89.00Size Type:Regular, Plus
- REI Co-opLightweight Base Layer Tights - Women'sTop Rated$44.95Underwear Weight:LightweightSize Type:Regular, Plus, Petite
Get $130 in value
$30 in card rewards are yours when approved for the REI Co-op Mastercard by Mar 9. Plus, you can earn a $100 REI gift card after your first purchase. Terms apply.
Apply now- REI Co-opLightweight Crew Base Layer Top - Men'sTop Rated$9.83 - $34.95Underwear Weight:LightweightSize Type:Regular, Big, Tall
- PatagoniaCapilene Midweight Zip-Neck Base Layer Top - Women's$49.83 - $99.00Underwear Weight:MidweightSize Type:Regular
- REI Co-opLightweight Crew Base Layer Top - Women'sTop Rated$34.95Underwear Weight:LightweightSize Type:Regular, Plus
- REI Co-opLightweight Half-Zip Base Layer Top - Women'sTop Rated$49.95Underwear Weight:LightweightSize Type:Regular, Plus
- PatagoniaCapilene Thermal Weight Zip-Neck Top - Men's$75.93 - $115.00Underwear Weight:HeavyweightSize Type:Regular
- Arc'teryxRho Zip-Neck Base Layer Top - Women'sTop Rated$120.00Underwear Weight:LightweightSize Type:Regular, Plus
- PatagoniaCapilene Thermal Weight Long-Underwear Bottoms - Men's$99.00Underwear Weight:HeavyweightSize Type:Regular, Big
- REI Co-opLightweight Half-Zip Base Layer Top - Men'sTop Rated$49.95Underwear Weight:LightweightSize Type:Regular, Big, Tall
- Free CountryCloud Knit Crewneck Base Layer Top - Men's$26.73Save 33%compared to  $40.00Underwear Weight:LightweightSize Type:Big, RegularREI OUTLET
- Kari TraaFryd Base Layer Top - Women's$44.93 - $60.00Underwear Weight:MidweightSize Type:Regular



























































































































































