Strong polyethylene body with reinforced core prevents buckling and bending. Ideal for positioning heavy appliances, opening car doors, installing windows and more. Valve for controlled inflation and deflation. Can be used as an alternative to plastic packers. Strong polyethylene body with reinforced core prevents buckling and bending. Ideal for positioning heavy appliances, opening car doors, installing windows and more. Valve for controlled inflation and deflation. Can be used as an alternative to plastic packers.