Desmond DAC-04 Dual Channel Arca & Slidefix Compatible 50mm Clamp QR 3/8" w 1/4" Adapter for Tripod Head DAC4 DAC-4 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. 2nd Channel accepts Arca Slidefix plates 3/8"-16 thread with metal 1/4"-20 Adapter Desmond Brand