This SAE Standard includes couplings, hitches, and safety chains used in conjunction with all types of trailers whose gross weight does not exceed 10 000 lb (4540 kg). This includes such types as utility, boat, camping, travel, and special purpose trailers which are normally towed by conventional passenger cars, light-duty commercial vehicles, and multi-purpose passenger vehicles. This standard is intended primarily for ball-and-socket type of couplings and hitches. It should not be construed as a limitation to this type alone, but should apply where appropriate to ring-and-pintle, clevis-and-pin, or any other draft means designed to serve this purpose.