This is a locking knob for all RAM "B" sized 1" socket arms and includes a brass 1/4"-20 thread that allows 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.

• Material: Powder Coated Marine Grade Aluminium
• Ball Size: 1" Rubber Ball "B" Size

Note: The "U" in the part number reflects product packaged in poly bag.