Harness: a device for fastening the child to the restraint system (the car seat), consisting of straps and a buckle. In groups 0 and 0+, it consists of two shoulder straps and a strap between the legs. In group 1 it consists of two shoulder straps, a strap between the legs, crotch strap, and two strips around the stomach. Both types include a buckle, which is a quick release device allowing the child restraint system to be secured, and which can be opened quickly.