The Mamiya MACRO 120mm F4 lens is a manual focus lens for medium format 645 cameras, ideal for macro photography. - Brand: Mamiya - Model Name: MACRO A 1:4 - Focal Length: 120mm - Aperture: Maximum f/4 to Minimum f/32 - Filter Diameter: 67mm - Focus Type: Manual - Included Accessories: Front cap, rear cap Although the size section is not applicable, the mount is Mamiya 645 mount, even though it's listed as X-mount. The exterior shows little signs of use, with few stains, scratches, and scuffs, and is very clean, with smooth operation. Unfortunately, due to long-term home storage, the lens has fungal mold. Please examine the photos carefully and make your judgment. Thank you for viewing.