This item is only compatible with the MVP Disc Station (any version). You must already have the Disc Station for the Add-On Module to be efffective. Designed to increase your storage capacity and to be used with any of our Disc Stations, the Add On Module III is two shelves built in the same sturdy metal material. Simply remove the top portion of your Disc Station and slide the Add On Module III into your existing unit to add upwards of 120 more discs to your premium shelving solution.