Our DX813 Vivitek Projector lamp replacements have the genuine original Osram brand bulb inside guaranteed to perform the same as your original Vivitek lamp. The lumen output (3,800 lumens) and rated lamp life (3,500 hours, 5,000 hours in Eco mode) is the same as the original Vivitek DX813 lamp. Beware of cheap generic lamps being sold elsewhere that offer less light output and reduced lamp life. We have been selling replacement projector lamps since 1997. Trust Pureland Supply with a 180 day warranty, 5-star Google rating, and free ground shipping.