The lightweight InnerCore base layer insulators are made of quick drying, 4-way stretch polyolefin. The brushed interior is cozy against the skin and moves moisture quickly. The jersey knit face fabric is durable and absorbs almost no water. Antimicrobial treatment inhibits the growth of bacteria. Worn alone, InnerCore tops offer UPF30+ rating, flat stitched seams, wide cuffs and paddling specific patterning.