? What's in the Box? TUSITA Small Rail Base with 1"Ball x1;TUSITA Double Socket Arm 1" - B Size Short x1;TUSITA Spine Clip Holder with B Size 1" Ball x1. ?Durability And Reliability? Made of High Strength Composite for durability and reliability in the most demanding environments. ?Features? Small version designed to quickly install to round rails FITS HANDLEBAR SIZES:22.2mm (?”), 25.4mm (1”), 28.6mm (1-?”), 32mm (1-¼”) (diameter); rubber pads provide stable gripping and protection of mounting surface. ?Compatibility? The addition of a 1" rubber ball that fits into any B size double socket arm enables seamless connection; the utilization of ball and socket technology grants limitless adjustability.