Product Description 【High-Quality Lens】 The Carl Zeiss prime lens offers superior optical performance, delivering sharp and clear images. 【Bright Maximum Aperture】 With a bright f/1.8 aperture, it performs excellently in low-light environments, allowing you to enjoy beautiful bokeh. 【Convenient Accessories】 Includes a lens cap, rear cap, and filter for easy protection and cleaning during use. - Brand: Carl Zeiss - Lens Type: Prime Lens - Focal Length: 50mm - Filter Diameter: 49mm - Accessories: Lens cap, rear cap, filter I am not very familiar with cameras, so I will answer questions to the best of my ability. I wasn't sure about the size section, so I put "Canon EF mount," but it was used with a CONTAX RTSⅡQUARTS. Thank you for looking. Size...Canon EF mount Other features...Front lens cap included, rear lens cap included