Activate by soaking in water for 2-5 minutes for hours of heat relief. Evaporative cooling process reduces effects of heat stress and fights fatigue. Lightweight, comfortable, cotton construction ensures comfort. Extra-long neck shade attaches conveniently to hard hat suspension and offers protection from UV rays. Fire-retardant "FR" version also available. Blue. 6717FR is made of acrylic polymer and need to soak for 2-5 minutes. 6717CT is made of PVA and needs to run under water for one minute.