Check the listing for details. RAM-B-201-ALA1-KRU RAM Double Socket Arm with Retention Knob - B.... Color: Black, Condition: New. Listed at 38.94 USD. RAM Double Socket Arm with Retention Knob - B... RAM-B-201-ALA1-KRU Genuine RAM Products! The RAM-B-201-ALA1-KRU, STANDARD length double socket arm with retention knob, has a socket at both ends that accommodates 1 INCHES ball bases. A single spring inside the arm opens the end sockets, allowing you to pivot the ball and socket connection. The knob extension allows for easy adjustment of the mount and prevents over loosening of the knob. This socket technology allows for almost infinite adjustment and perfect viewing angles.product dimensions Overall Length: 3.73 INCHES socket to socket length 3 INCHES ball size B Size (1 INCHES )weight capacity Standard Use: 2 lbsHeavy-Duty Use: 1 lbmaterials Marine-grade aluminumpackaging type Poly BagWeight 0.34 lb product dimensions Overall Length: 3.73 INCHES socket to socket length 3 INCHES ball size B Size (1 INCHES ) weight capacity Standard Use: 2 lbsHeavy-Duty Use: 1 lb materials Marine-grade aluminum packaging type Poly Bag Weight 0.34 lb