RAM Mount Square Post Clamp Mount f/Posts Up to 2.5" Wide [RAM-101U-247-25]Square Post Clamp Mount for Posts Up to 2. 5" Wide The RAM 101U 247 25 consists of a double socket arm, round 2. 5" diameter round base with the universal AMPS hole pattern and 2. 5" clamp base. The clamp base will wrap around a maximum width of 2. 5" and is tightened by screwing the two plates together with the included nuts and bolts. Rubber ball, socket technology dampens shock and vibration, as well as allows for almost infinite adjustment,