A must have for your vehiclemany of you may know, there are specific jack points for the vehicle model 3/Y/X/S. Without an adapter, you may risk damaging the battery of the vehicle when raising it to rotate tires Protect battery and paint from damagethe rubber O-ring helps you preinstall the lift adapter which allows for an easy placement of either the floor jack or lift Dimensions are 2.7 diameter. 1 tall not counting the portion that goes into the hole. Can be used with floor jack or 2-post lift. 1 piece for personal owner with a floor jack or all 4 for a 4-point professional vehicle lift in the auto repair shop NOTEFor Model X, it might be a little bit loose for the hole and you might need to line up the pad in the hole while raising the the car Storage bag keeps jack lift pads organized. Easy to store in your trunk or garage.