This is the rubber seat bumper that cushions the seat legs on the driver and passenger seats to the floor. The bumpers slide on the legs that are on the back side of the seat. For 1955-1964 drivers seats one is required and the later 1965-1975 seats do not have one. For the passenger side 1955-1964 earlier seats have only one and later seats have 2 due to the extra leg. For 1965-1975 passenger seats 2 are required. Check quantities on your seat to get the proper amount.