This is the Omega D-5 / D-6 single lens slide-in lens mount that is often used for short focal length lenses less than 50mm. In order to attach the lens to the lensmount, the lens must first be mounted on the appropriate lens plate. In use, since the the rear element of the lens will extend beyond the lensmount, you first insert the lensmount and then attach the lens plate with lens to the lensmount with the included lens plate securing screws. Use the #421-107 slide in lens mount for 50mm to 150mm lenses.
The used lens mounts have minor cosmetic marks from previous use, but are certified to be in perfect working condition.
Please refer to our D-5 / D-6 Lens Mount Reference Chart to determine the recommended lens plates for specific lenses.