This is a Stoltz Brand 12 inch Skid pad designed to fit on your 4 inch wide boat trailer cross-member. Stoltz makes there products from the highest quality ingredients. The Soltz mixture contains extreme heat resistant elements which prevent dry rotting or cracking. This Stoltz Skid pad is the real deal, will not mark up your boat, or fail you like PVC may. This product is specifically for mounting on 4 inch cross-members to protect the boat hull from contacting the cross-member. This can cause damaged to the boat hull. The Stoltz material is extremely tough and does not wear down or crack up.