RAM® Square Post Clamp Base for Posts up to 4" Wide Without Hardware RAM-114-RBU The round base adapter contains

The round base adapter contains the industry standard universal AMPS hole pattern

The RAM® X-Grip® universal holder for 9"-11" tablets features an 'X' design that expands and contracts to provide a perfect fit for your device – even if it's in a case

Compatible with RAM-B-347U and RAM-347U

allowing your laptop to close completely while in the tray

connected to a 1/4"-20 camera thread

RAM® Square Post Clamp Base for Posts up to 4" Wide Without Hardware RAM-114-RBU The round base adapter containsThe RAM 247U 4NH is a clamp base with 1. 5" rubber ball that will connect to rails up to 4" maximum in width. Hardware not included.