Description 1Wide Application: 1in ball adapter fits for 915mm/0.350.59in diameter rails, bikes, scooters, mobile phones, navigations, rearview mirrors, etc. 2Premium Material: Double ball bracket is made of aluminum alloy and rubber material, wear resistant, rustproof, sturdy and durable. 3Excellent Performance: Ball mount base can prevent loosening in high vibration, anti slip and provides a secure grip with slight flexibility. 4Professional Design: Professional manufacturing, exquisite workmanship, weather resistant, can be used in harsh environments, stable and reliable. 5Simple Installation: The installation is simple, M4 mounting hole, no complicated operation is required, convenient for using, save your time.