Wheelchair Rail & Tube Mount with Extension & Model Specific iPad 2 Cradle (sku 21784)Wheelchair Rail & Tube Mount with Extension & Model Specific iPad 2 iPad 3 iPad 4 Cradle This mount features a tool less Small Tough Claw base with 1. 5" rubber ball, two double socket arms, a double ball adapter for extra length and articulation together with a Model Specific Roller design iPad 2 iPad 3 iPad 4 Cradle The patent pending roller design allows for smooth placement and removal of the iiPad 2 iPad 3 iPad 4 while keeping it secure when on