does the 16x9 base plate fir onto a arri dovetail?
This is directly from 16x9's web site:
Mounts onto Bridgeplate Systems
Designed to mount onto studio base plates, from ARRI or Chrosziel, the 15mm Cine Base comes standard with two thread hole patterns. The first row features 1/4"-20 and 3/8"-16 female threads and the second row features 3/8"-16 female threads.