This is a brand new replacement lamp module manufactured to exactly the same specifications as the projector manufacturers original to give 100% performance. A Diamond lamp uses the manufacturer�s original bulb and fits it inside a high quality Diamond Lamp housing guaranteeing that the lamp not only delivers on price but also on quality. Diamond Lamps are so confident in their product that they even offer an extended 180 day warranty. This lamp is 100% compatible with the following VIVITEK projector models D-851 D-853W D-855ST D-856STPB D-857WT D-858WTPB. Matching Part Number(s) 5811116713-SU .