The arm rest must be ordered when replacing the wrist strap on the SoftGuard® Safety Restraint Chair. Because of the design of the included strap, you must purchase a specific left or right Arm Rest with XL-Strap. This is the Left. This strap is 12" longer than our regular length wrist strap (40"). Does not include a cam and spring set. These must be ordered separately and roll pins are no longer needed or used.