An evolution of the original, Trail Tank 2 uses a lighter, softer, and stretchier fabric with improved chafe-resistance. Built for long, hot days on the trail. Cut and sizing remain true to the original Trail Tank. 80gsm 93% polyester / 7% spandex Low-abrasion bonded seams Gender-specific cut Sizing: Trail Tank sizing is designed to match Iced Tees. For example, if you're a size Medium Iced Tee, you should also be a size Medium Trail Tank.