Simms Challenger Solar Tech JerseyUPF 50 crewneck with easy breathing side panels that keep you cool, collected and comfortable.FeaturesPerforated fabric at underarm and side panelsRaglan sleeves promote range of motionBuilt-in thumb loopsMachine wash & dry. See garment label for details.FABRIC TECH: Body fabric- 135 gsm 100% polyester; Under arm fabric- 160 gsm 94% polyester/6% spandex