Used with BTBUMPER :
- Insert bottom bumper coupler BCOUP3 into the 3 fixing points located at the back of the BTBUMPERs.
- Insert the steel pins into the corresponding holes.
- Insert safety pins into steel pin hole and lock safety by rotating its ring around steel pin.
- Attach the lower hook of the chain to the rear of BCOUP3, with the steel pin and the safety pin.