The RAM® Torque™ handlebar mounting base features a 1" / 2.54cm / 2.54cm / 2.54cm B size RAM® rubber ball and is compatible with rails 3/4” to 1” in diameter. Sizing inserts are included to provide a tight fit while also protecting the mounting surface. The RAM® Torque™ mounting base also includes nylon-insert lock nuts to prevent loosening in high vibration environments.