Check the listing for details. RAM Drill-Down Dashboard 1.5" Ball Base with Backing Plate RAM-202-225-2U. Color: Black, Condition: New, Made in United States. Listed at 26.99 USD. Add strength and stability to your mounting surface with the RAM Backing Plate Adapter. Great for dashboard mounting as well as many other applications Features: ---2.5" diameter round plate with 1.5" ball (C size) and the universal AMPS hole pattern* - Ball connects to RAM C size socket arms(sold separately) ---2.10" x 2.60" x 0.15" backer plate with two hole patterns - a 4-hole AMPS pattern with #8-32 theaded holes pattern and a 4-hole 2" x 2.5" pattern with #10-24 threaded holes ---Constructed of marine-grade aluminum and steel ---Holds up to 4 lbs. ---Made in the USA * Round Plate Hole Pattern: ---4-Hole AMPS: 1.181" x 1.496" ---3-Hole 120-Degree: 1.812" Diameter Included Hardware: ---(1) 2.1" x 2.