ECCPP 2pcs Liftgate and 2pcs Window Glass Lift Supports Struts for GMC Yukon 1500 2500 for Chevrolet Suburban 1500 2500 for Chevrolet Tahoe for Cadillac Escalade 2000-2004. FUNCTION – Use compressed gas, contained in a cylinder and compressed by a piston, to exert a force to support the weight of front hood or rear liftgate tailgate trunk hatchback doors while they are open, no need to hold the door up with your head.