Arm board, can level 180 ° Unfold, pull rod design, release to position, suitable for operating table side rail size 25 * 8, 25 * 10, 30 * 10, 30 * 8, 28.5 * 9.5, 28 * 9.5, 32 * 9mm, board size 600 * 150 * 10mm, memory sponge pad thickness 30, 40, 50, 60, 70, 75, 80, 90mm.