Rear side: M65x1 male thread (65mm 1mm thread pitch).
Distance between flanges:10mm.
Height:14mm. Weight:25g..This adapter allows using LOMO projection lenses that have 62.5mm barrel diameter on Chinese focusing helicoids with M65x1 screw thread. Such setup is great for portrait and macro shots..The adapter is secured by 3 set screw (installed) with an allen key (included)..The intermediate plastic gasket protecting a lens body from damage by screws..This is a very high quality anodized aluminum adapter..Brand new, never used.