Wheelchair U-Bolt Mount with Double Socket Swivel Arm & Universal Phone Holder (sku 21559)Wheelchair U Bolt Mount with Double Socket Swivel Arm and Universal Phone Holder. The Universal phone holder is compatible with many phones fitted with or without a case or skin as the spring loaded side grip arms open to a maximum of 90mm and close to a minimum of 54mm. The side grip arms and support feet are cushioned to protect the phone. A push button releases the spring grip to make phone removal quick and easy. The Double Socket Swivel Arm