Designed to prevent heat exhaustion and fatigue, these vests provide safe and effective cooling comfort while keeping you visible on the jobsite. California Residents Proposition 65 Warning Features: Thermostat evaporative cooling polymer provides fast and effective cooling Simply submerse in water and wring out excess for hours of cooling comfort Cooling material holds snug to your body for fast and effective relief Specially designed polyester pongee fabric is comfortable and durable Premium Startech reflective tape provides maximum visibility Nylon lining coated with PTFE material provides a waterproof yet breathable design Full zipper front for easy on/off Pioneer Thermostat Cooling Safety Vest