For using Nikon Z mount mirrorless digital cameras with all M39 (39mm) mount lenses.
Switching shooting mode and focusing mode to M (manual) is recommended.
Allows focus infinity.
Not suitable for Nikon F film / digital SLR cameras and 1 mount mirrorless cameras.
Since there is no diaphram control, you can use the maximum aperture of Canon EF / EF-S lens only.