Desmond DBC-50 50mm Dual Double Subtend Clamp Arca Compatible 1/4" / 3/8" All Metal (aluminum) Construction No Rubber or Plastic Parts. will accommodate any Arca style plate from various makers including: Really right stuff (RRS), Wimberley, Jobu Design, Arca Swiss, Kirk Enterprises, Markins, etc. 50mm (1.97") in Length. 3/8"-16 thread with metal 1/4"-20 Adapter Under and over independent Arca clamps.