Check the listing for details. RAM-103-B-238U RAM Double Socket Arm with Diamond Ball Plate.... Color: Black, Condition: New. Listed at 48.44 USD. RAM Double Socket Arm with Diamond Ball Plate... RAM-103-B-238U Genuine RAM Products! The RAM-103-B-238U consists of the 1.5 INCHES C size diameter ball and socket system with one open socket end; RAM-201U-B socket arm is short length at 3.56 INCHES end to end with 2.5 INCHES socket-to-socket length. This mount is designed to be used with any of the C size RAM Mount bases or cradles with a 1.5 INCHES diameter rubber ball. The RAM-238U RAM Diamond Ball Base features industry standard AMPS 2-hole pattern and can be used as an adapter to attach a holder, or a mounting drill-down base.socket to socket length 2.5 INCHES hole pattern 2-Hole AMPS 1.912 INCHES plate size 2.43 INCHES x 1.31 INCHES ball size C Size (1.5 INCHES )weight capacity Standard Use: 4 lbsHeavy-Duty Use: 3 lbsmaterials Marine-grade aluminumpackaging type Poly BagWeight 0.7 lb socket to socket length 2.5 INCHES hole pattern 2-Hole AMPS 1.912 INCHES plate size 2.43 INCHES x 1.31 INCHES ball size C Size (1.5 INCHES ) weight capacity Standard Use: 4 lbsHeavy-Duty Use: 3 lbs materials Marine-grade aluminum packaging type Poly Bag Weight 0.7 lb