Reverse mount adapters for Ultra-Micro-Nikkor
For macro photography
These dedicated adapters are longer than the ones for enlarging lenses, in order to fit properly the recessed front filter thread on the Ultra-Micro-Nikkor lenses. They are not recommended for use with enlarging lenses.
Long 40.5mm x 0.5 reverse mount adapter
Available with M39 (LTM) mount, M42 mount or T2 mount. Available in aluminum or brass.
For Ultra-Micro-Nikkor 28mm.
The 40.5mm thread is 5mm long, in order to fit properly the recessed front filter thread on the Ultra-Micro-Nikkor lenses.
Not recommended for use with enlarging lenses, as on enlarging lenses the longer adapter may jam onto the metal ring of the front element.

A solid adapter, made in aluminum, with 5mm long 40.5mm x 0.5 male thread on front to fit the lens front filter thread. Available with male M39 Leica thread mount, M42 (42mm x 1) thread mount or T2 (42mm x 0.75) thread mount on the other end. You can leave the adapter mounted on the lens and use a threaded cap (not included) on it. The adapter is partially painted matt black on the inside.