This product is an extension tube for close-up photography, used in conjunction with FD lenses. It has a thickness of 25mm and supports open aperture metering and automatic diaphragm linkage shooting. Compatible lenses are single-focus lenses with focal lengths from 35mm to 200mm. The exterior has no noticeable scratches, but there are minor scratches and scuffs. The 7th and 8th photos are samples taken with a 50mm f/1.8 lens attached to a mirrorless single-lens camera via a mount adapter. Included accessories are caps (F, R).