This Universal Lateral Positioner assures stability on 3 planes. Fast, easy setup. Locks securely to the OR side rail with mount.Radiolucent Design. The base plate is 25" wide and the internal patient width is 18". The upper lateral arm is adjustable on 2 planes. You can adjust it in and out 2" ( from 9" to 11" from the back plate). You can also adjust the height of this arm vertically from 8.75" to 12 1/4" (height from the base plate to the bottom of the square brace plate.)This product functions similarly to the IMP^® or McGuire Lateral Positioners.