Elevation assist allows clients with poor grade deltoid muscle strength to achieve greater range of motion. This new design is universal left or right, and has more lifting power with fewer rubber bands. The addition of the new Forearm Support Slide simplifies forearm balancing, without tools. The JAECO/Rancho Mount (B9202-97) sold separately will simplify balancing of the Mobile Arm Support. Sizing: Measure distance from Olecranon Process to Ulnar Styloid minus 1 1/2". Note: If measured distance is 1/2" longer, choose next larger size. Mounts sold separately.