TAKAHASHI DX-WR WIDE MOUNT T-RING FOR CANON EOS

The Takahashi wide mount t-ring adapts the Takahashi wide mount (WM) thread to a Canon EOS or Nikon digital SLR.  The wide mount design is an improvement over previous designs and produces a larger image circle. 

Metal back length = 12 mm
Male M54 to Canon EOS bayonet