Conforms to NFPA 1901 and FHA, 49CFR specifications. Made of die cast high strength zinc/aluminum alloy. Tested to withstand over 2000 lbs. static load. Over 42 square inches of serrated non-skid step pad area. Heavy duty stainless steel spring holds step open or closed. Unit will not rust or corrode. Furnished with molded rubber mounting gasket to protect truck body and enhance appearance. Designed for mounting with 5/16" dia. carriage bolts (not supplied).