The RAM-101U-247-4 consists of a double socket arm, a round 2.5" diameter base with the universal AMPS hole pattern, and a 4" clamp base. The clamp base will wrap around a maximum width of 4" 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 for perfect viewing angles.