The PENTAX 645 A 200mm f/4 lens boasts excellent descriptive power and high durability. When held up to the light, there appears to be a slight amount of mold. The size input doesn't have 645, and I can't list the item without selecting an option, so I've chosen Q mount, but it is a 645 mount, not a Q mount. Manual focus only. - Brand: PENTAX - Model: 645 A 200mm f/4 - Focal Length: 200mm - Maximum Aperture: f/4 - Mount Type: 645 mount Thank you for looking.