Check the listing for details. RAM-201LU RAM Double Socket Arm with Brass Key Lock Kno.... Color: Black, Condition: New. Listed at 69.44 USD. RAM Double Socket Arm with Brass Key Lock Kno... RAM-201LU Genuine RAM Products! The RAM-201LU, standard double socket arm with locking knob, has a socket at both ends that accommodates 1.5 INCHES ball bases. A single spring inside the arm opens the end sockets, allowing you to pivot the ball and socket connection. This socket technology allows for almost infinite adjustment and perfect viewing angles. The locking knob, includes a brass 1/4 INCHES -20 thread; this allowing you to disengage the screwing of the knob. Once you have set your mount in the location you need, you can lock it in place and feel safe that your mounted device will stay right where you left it.hardware included (2) Keysproduct dimensions Overall Length: 5.69 INCHES socket to socket length 4.66 INCHES ball size C Size (1.5 INCHES )weight capacity Standard Use: 4 lbsHeavy-Duty Use: 3 lbsmaterials Marine-grade aluminumpackaging type Poly BagWeight 0.9 lb hardware included (2) Keys product dimensions Overall Length: 5.69 INCHES socket to socket length 4.66 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 0.9 lb