[von Lutz]

Not sure what you mean by a parachute "buckle" but it's not the buckle that holds the parachute straps together. In the US it's called a "D" ring because of its shape. It's connected by a cable to the pin that holds the parachute pack closed. Usually it's attached to the left shoulder strap about mid chest so you can grab and pull with your right hand once you're clear of the aircraft.