100% Certified recycled PET polyester. BIZ COOL™ Breathable sports knit 155 GSM. UPF Rating: 50+. Breathable BIZ COOL™ sports knit keeps you cool and dry. Self-fabric rounded neck opening fits comfortably and sits neat. Longer length can be worn out or tucked in. This garment is made from 100% recycled polyester resulting in the equivalent of 10 plastic bottles being diverted from landfill.