Desmond DAC-38 38mm QR Clamp 1/4" Screw Hole & 3 Strap Bosses All Metal (aluminum) Construction No Rubber or Plastic Parts. will accommodate any Arca style plate from various makers including: Really right stuff (RRS), Wimberley, Arca Swiss, Kirk Enterprises, Markins, etc. 38mm (1.5") Long. 1/4" Screw Hole. Flat bottom with no registration slots.