The Torque Handlebar/Rail Mounting Base with 1' Ball from RAM Mounts utilizes a rubber ball and socket system to securely attach to your vehicle's handlebars or rail measuring 0.375 to 0.625' in diameter. Sizing inserts are included to provide a secure fit and to protect the rail. The mount utilizes nylon-insert locknuts to prevent loosening in high-vibration situations, such as when you're riding across rough terrain. The 1' B-sized rubber ball is compatible with various mounts and arms (sold separately) to hold devices like smartphones, tablets, and cameras.