This adapts an older style Nikon 80-200 f2.8 lens to a Manfrotto quick disconnect tripod mount. These older lenses did not come with a tripod leg, which means the lens hangs off the camera body when mounted on a tripod, stressing the camera body. There's not much room to grab this lens, as you need to leave space for the zoom-focus ring. This adapter covers the f-stop ring and AF/MF switch. You set the f-stop to max and lock it, and set the focus switch to AF before mounting. It then attaches to the camera and provides a mounting point off the camera body.