This lens ring plate is a part of the complete Lens Ring. You will only need it if you are building your own or upgrading. You will also need to buy a metal lens ring and plastic insert for your lens. Lens rings also work on Nodal Ninja Ultimate M1. A correct length of the plate is needed for proper no-parallax point setting for your lens. Refer to our Manuals section for choosing the right lens ring plate or email us to ask.