This adapter allows to use OCT-19 lenses on Redrock Micro M2 Depth-Of-Field adapter. It is made of light alloy. Weight is 230 gr.
OCT-19 lenses have different designs. So, part of them fit this adapter, other - don't fit. One of distinctive features is pictured below. Compare rear parts of these lenses. Top lens has external rail in the rear part. Some of such lenses will not fit this adapter, though we made as big cut-out as original M2 allows. Lower lens will fit. Another issue are tele lenses that have their rear block protruding too deep into the camera at short focus distance. You'll be able to use tele lens focused to infinity or bit closer, but not down to their minimal focus.
These problems related to M2, not to our adapter. There is just no way to make better adapter based on the current design of Redrock Micro M2.