RAM Mount Square Post Clamp f/Posts Up to 3" Wide w/Arm [RAM-101U-247-3]Square Post Clamp for Posts Up to 3" Wide with Arm The RAM 101U 247 3 consists of a double socket arm, round 2. 5" diameter round base with the universal AMPS hole pattern and 3" clamp base. The clamp base will wrap around a maximum width of 3" 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, perfect