This item is provided by Crutchfield.com and includes free phone technical support for the life of the product. Details on how to take advantage of this service will be included with your package. Should you have any issues locating information on how to contact Crutchfield Technical Support, please contact this website's Customer Service department. The Salamander Designs SA/XR30 extended rear pane gives you room for your larger components in select 3-shelf Chameleon racks and Synergy cabinets, like the Model 303 . It replaces the regular panel, giving you an additional 3-1/2 of depth. Ventilation slots help your components remain cool. Thumbnut screws hold the panel securely in place. Thumbnut screws make it easy to attach or remove the panel with a twist of your fingers. What's in the Box: 1. Extended rear-panel 2. 4 Thumb-nuts 3. 4 Flat-nuts 4. 4 Drop-in nuts 5. 4 Washers 6. 4 Studs 7. Magnet 8. Hex-key 9. Installation Instructions