Auxiliary Telephoto Lens for Mamiya 528TL SLR Camera by Vivitar. This screws into the front of the camera lens and changes the focal length from 48mm to 82mm. This threads into a 52mm diameter filter threaded lens. It protrudes to the rear about 18mm. There is a small dent in the front filter rim as shown in the photographs, otherwise very good condition with original front and rear caps.