The RAM^® Torque^™ bar mount has a 1" rubber ball and accommodates rails 3/8" to 5/8" in diameter. Sizing inserts are included to provide a snug fit and protection of the rail. The mount utilizes nylon-insert locknuts to prevent loosening in high vibration environments. The RAM-B-408-37-62U allows for mounting to scooter mirror rails as well as vehicle headrests and other round rails within the stated dimensions.