The RAM locking knob, includes a brass 1/4"-20 thread, for 1" (B size) socket arms; 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.
We've gone "ala carte" with most of our RAM pieces, build your mount however you want it! Please let me (firstname.lastname@example.org) know if there's something you'd like that isn't listed, or if you have questions about how to build your personal mount.
RAM Mounts Locking Arm Knob
Produced by RAM Mounts of USA