This is a new version of 15mm single rod clamp w/ four 1/4" thread for DSLR Rig. You can install an articulating arm on the female 1/4" thread, and then a monitor or a LED on the articulating arm.
The rod clamp could be mounted on 15mm rod, locked with a wingnut. The built-in 1/4"-20 threaded hold could be mounted with magic arm with 1/4" screws for monitor. Isn't it fantastic?
It's the little parts like this that make my rig more flexible and versatile!