Phase Change Cooling Vests TechNiche's Phase Change Cooling Vest Inserts maintain a comfortable 58 degrees F (14 degrees C) for up to 3 hours of critical heat stress relief. They are commonly used under high heat protective clothing, hazardous material suits, military body armor, and mascot costumes.   Phase Change Cooling 6626 Standard Phase Change Cooling Vests V-neck w/zipper closure; hook & loop girth adjustments 100% cotton (excluding inserts) Royal Blue and Black M/L (100-175 lbs.), L/XL (175-250 lbs.), 2XL (250-300 lbs.) Include one (1) set of Phase Change Cooling Inserts (6665)     Phase Change Cooling 6626-I Standard Vests w/INDURA™ Fire resistant; V-neck w/zipper closure, and hook & loop girth adjustments INDURA™ fire resistant fabric M/L (100-175 lbs.), L/XL (175-250 lbs.), 2XL (250-300 lbs.) Include one (1) set of Phase Change Cooling Inserts (6665)     Phase Change Cooling 6626-N Standard Vests w/NOMEX™ Fire resistant; V-neck w/zipper closure, and hook & loop girth adjustments NOMEX™ fire resistant fabric, thread, and hook & loop for complete protection M/L (100-175 lbs.), L/XL (175-250 lbs.), 2XL (250-300 lbs.) Include one (1) set of Phase Change Cooling Inserts (6665)     Phase Change Cooling 6665 Standard Cooling Vest Inserts Use additional inserts for continuous relief Include four (4) Phase Change Cooling Inserts per set For PCC Standard Vests (6626, 6626-I, 6626-N)     Phase Change Cooling 6627 Cooling Vests w/Built-In Hydration System Built-in hydration pocket and drinking hose w/valve; V-neck w/zipper closure, and hook & loop girth adjustments 70 fl. oz. (2 liter) bladder; 100% cotton (excluding inserts) Royal Blue M/L (100-175 lbs.), L/XL (175-250 lbs.), 2XL (250-300 lbs.) Include one (1) set of Phase Change Cooling Inserts (6665) & Hydration System (6660) Can be ordered in NOMEX™ (6627-N) and INDURA™ (6627-I) fire resistant fabrics     Phase Change Cooling 6660 Hydration Systems Replacement bladders w/hose and valve Purchase individual hydration systems for persons sharing vests, or as needed Include one (1) 70 fl. oz. (2 liter) bladder w/hose and valve For Phase Change Cooling Vests w/Built-In Hydration System (6627)     Water Based Cooling 6826 Fire Resistant Vests w/INDURA™ Ideal for hot and flammable job sites; inserts maintain a temperature of 32 degrees F (0 degrees C) for approximately 1 hour INDURA™ fire resistant fabric M/L (100-175 lbs.), L/XL (175-250 lbs.), 2XL (250-300 lbs.) Include one (1) set of Water Based Cooling Fire Resistant Vest Inserts (6865)     Water Based Cooling 6865 Replacement Fire Resistant Vest Inserts Use additional inserts for continuous relief; place in freezer before use Include four (4) Water Based Cooling Inserts per set For Water Based Cooling Fire Resistant Vests (6826)