BPM Leica M39 extended female

Leica M39 lens adaptor with 5mm thick extension and a female thread to attach a Leica 39mm screw thread lens to a set of BPM bellows. These may be inscribed, Leica, M39, or Zenit. Ideal for attaching an enlarging lens to the front of a set of BPM bellows. The 5mm extension version is not a common BPM accessory. Made for use with a Leica body that needs clearance from the bellows.