Light, durable recycled polyester double weave is breathable, stretchy, and provides UPF 40 sun protection Snap front placket for easy on-and-off Zippered side-entry chest pockets stow small essentials, are accessible while wearing a pack, and have mesh backing for added ventilation Shoulder seams are shifted forward for comfort under a pack Side slit at hem for freedom for movement Regular with articulated patterning for mobility and comfort