The Miller CX Accessory Mounting Block for CX and Compass Fluid Heads allows you to mount additional accessories like a viewfinder, monitor, or light onto your CX or Compass tripod fluid head. This solid metal alloy block attaches to either side of your fluid head, allowing you to mount up to 3kgs of accessories using its 1/4"-20 and 3/8"-16 mounting threads. You can even attach one to each side of the head simultaneously for even more accessory mounting options.