Wm's AirExchange UPF50 TankAir it out on the trail, at the crag, or by the waterthis go to base layer keeps your core covered while letting your arms fly free. AirExchange performance fabric is breathable and quick drying, so you can stay active without accumulating heat or moisture. When the sun pops out and outer layers come off, UPF 50 protection keeps you safe from blazing rays. Dropped shoulder and abrasion resistant seams keep you comfy, agile, and chafe free when youre