These are great, absolute beauties. Complete with lenses, front surface mirrors, color wheel, fans, complete circuit board with DDP3021 DLP chip, IC's, heat sink, #29912725103 DMD chip, and lots of other parts. We believe these were made for 50 inch rear projection TVs. Front lens clear diameter is 48mm. Assembly is 14 inches long by 8 inches wide by 8 inches high. Does not include a light source. Unused. Limited quantity. This was made for RCA 50" and 61" DLP projection TV Models M50WH185YX1 M50WH185YX2 M50WH187YX1 M50WH72SYX1 M50WH72SYX2 M50WH73YX1 M50WH74SYX1 M50WH74YX1 M61WH185YX1 M61WH74SYX1 and M61WH74YX1. If you have one of these TVs then you should get this as it is unused and priced way below market prices and are becoming very hard to find. If you take one apart you'll find lots of optics, electronics, color wheel, and mechanical parts to wet your creative juices.