A UPF 50+, 8oz brushed Evotherm fabric with flatlock seams provides maximum protection against wetsuit rubbing, rashes and the sun's rays. Thumb loops prevent slippage when worn under a wetsuit. This superb UV shield gives you UPF 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.