A superb UV shield giving you UPV 50+ sun protection. 8oz Evotherm fabric with flatlock durable seam construction provides maximum protection against wetsuit rubs and rashes as well as sun. Thumb loops to keep in place when worn under a wetsuit. FLATLOCK: seam construction EvoTherm X fabric: 4-Way Stretch Thermal, Breathable, Wind Block UV shield: UPF 50+ sun protection. This garment offers 4-way stretch, is thermal, breathable, and provides wind block protection. It ensures UPF 50+ sun protection.