The CameraKey Tool from Fotodiox is made for Hasselblad cameras and lenses. A lens can only be taken off or mounted onto a Hasselblad body when both the body and lens are cocked, although sometimes the shutter is released on the body while the lens is still cocked. This tool allows you to cock the lens and the body so that you can mount or un-mount the lens. One side of the tool is for cocking the lens and the other side is for cocking the body. A leather carrying case is included with the tool.