Adds 1 of thickness to jack foot. For 12 round jack feet. Both pads shake tested to 50Gs and temperature tested to 120 and -40 degrees F.This item is in the category "eBay Motors\Parts & Accessories\RV, Trailer & Camper Parts & Accessories\Trailer Leveling & Towing\Jacks, Leveling & Chocks". The seller is "iglr" and is located in this country: US. This item can be shipped to United States.