This is an aluminum Truss Shelf previously used for holding projector comes with steel truss clamp by TUVRheinland truss clamp for 2" tube, used for bottom mounting the aluminum shelf has a 5/8" lip around the edge to prevent slipping of your projector Measures 15-1/4" long by 11-1/4" wide with 7/8" lip (rectangle shape) This shelf has been used by DJ to hold projector, black aluminum with steel truss clamp Shipping: If you are buying more than one item, please remember to check off the area that requests the seller to send an invoice, so I can combine the order for you before you pay Thank you again for browsing in my store, there is always something new and exciting coming your way! Feel free to ask questions, and let me know if there is a problem with an order before putting in a claim with, so we can work things out. Thank you again Estate Treasures by Alana