2024 Dodge RAM 2500: What To Expect For The Future Of Heavy Duty Trucks 2026 Ram 2500 Pickup Truck Overview Ram Canada 2026 Ram HD Tradesman 4x4 Crew Cab 6'4" Box Features and Specs 2026 Ram HD Launches With Two Low Priced Trim Packages New 2026 RAM 2500 Limited Crew Cab in Crestview # Chrysler Dodge Jeep 2025 RAM 1500 Towing Capacity Ultimate Guide. RAM Double Socket Arm with Locking Knob for 1. 5" Ball Bases The RAM 201LU, standard double socket arm with locking knob, has a socket at both ends that accommodates 1. 5" 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" 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. Dimensions: Overall Length: 5. 625" Socket To Socket Length: 4. 5" Material: Powder Coated Marine Grade Aluminum Ball Size: 1. 5" Rubber Ball Size Note: The "U" in the part number reflects product packaged in poly bag.