The ultimate climbing T-shirt made from a unique breathable, climate control fabric. Stretch-Air patented climate-control 'Distance Fibers' use Cocona, a special fiber made from coconut husks - yes, coconut husks. Cocona transports all moisture away from the skin and is comfortable and soft on the skin. Cocona is organic and eco-friendly. The elastic quality of Stretch-Air fabrics make them ideal for tree climbing- great fit with complete freedom of movement. This shirt was specifically designed for tree climbing. High collar and zip neck prevents debris from entering via the neck opening.