Check the listing for details. RAM-101U-UK2 RAM Double U-Bolt Mount with Double Ball Adap.... Color: Black, Condition: New. Listed at 120.44 USD. RAM Double U-Bolt Mount with Double Ball Adap... RAM-101U-UK2 Genuine RAM Products! This kit contains a short double socket arm connected to a medium double socket arm with a double-ball adapter. On the bottom is our c-size double u-bolt base and on top is our 1.5 inch ball with 2.5 inch AMPS mounting plate.hardware included (2) 1/4 INCHES -20 U-Bolts for 1 INCHES - 1.25 INCHES Rails(4) 1/4 INCHES -20 Nylock Nuts(4) Rubber Capsclamp range 1 INCHES - 1.25 INCHES diametersocket to socket length Medium Arm: 4.66 INCHES Short Arm: 2.5 INCHES hole pattern 4-Hole AMPS: 1.181 INCHES x 1.496 INCHES 3-Hole 120-Degree: 1.812 INCHES Diameterball size C Size (1.5 INCHES )weight capacity Standard Use: 4 lbsHeavy-Duty Use: 3 lbsmaterials Marine-grade aluminumpackaging type Poly BagWeight 2.3 lb hardware included (2) 1/4 INCHES -20 U-Bolts for 1 INCHES - 1.25 INCHES Rails(4) 1/4 INCHES -20 Nylock Nuts(4) Rubber Caps clamp range 1 INCHES - 1.25 INCHES diameter socket to socket length Medium Arm: 4.66 INCHES Short Arm: 2.5 INCHES hole pattern 4-Hole AMPS: 1.181 INCHES x 1.496 INCHES 3-Hole 120-Degree: 1.812 INCHES Diameter 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 2.3 lb