The RAM® Torque™ handlebar mounting base features a 25.4mm B size RAM® rubber ball and is compatible with rails 19.05mm to 25.4mm 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 locknuts to prevent loosening in high vibration environments. It’s made of powder-coated, marine-grade aluminum for durability and reliability in the most demanding environments.