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