Accessory type 1: Seat belt tongue
Tongue is the part which is pushed into the Buckle when connecting the Seat Belt and is ejected when the quick release is used.

Accessory type 2: Seat belt buckles
Buckle is a female connector for seat belt, into which the tongue is pushed when connecting the Seat Belt.Generally located just on or below the hip on Seat Belts or on the lap of Harnesses.

Accessory type 3: Seat belt pillar loops