All explanations are by AI. m(_ _)m This item was passed down from my sibling, so I don't know the details. I haven't confirmed its operation. Please purchase only if you understand! Bundle sales are also possible, so feel free to request! Please check the condition of the item in the photos. Please purchase after you are satisfied. If you are looking for perfection or are overly concerned about details, please refrain from purchasing. The KENKO 2x Teleplus Pro 300 offers excellent image quality. - Brand: KENKO - Model Name: TELEPLUS PRO 300 - Magnification: 2x - Country of Manufacture: Japan This is a Kenko "2X TELEPLUS PRO 300" teleconverter. By attaching it between the lens and the body, you can extend the focal length of the master lens by a factor of 2. The F-number becomes two stops darker (e.g., an F1.4 lens becomes equivalent to F2.8). Thank you for viewing.