Review on OPTOMA Technology Replacement Projector Lamp for TX542/EX542/TX540/GT360/GT720/ES523ST/EW533ST/GT700/TX542-3D PRO450W/PRO180ST (BL-FP180E) - High-Quality Lamp Replacement for Optimal Projection Performance by Chris Horton

This appears to be an OEM part. The only difference between it and its replacement is that it takes a minute for the bulb to warm up to temperature and the colors to even out. It could just be my nitpicking, the fact that it's still fairly new, or that it really can't be an exact replacement for the original. I like the original. It still works but its light is quite dim (especially in dark situations when the lights in the room are on) so a replacement was needed (I had a full life and they lost the bulb a bit and it still works ). This will be a fallback if something happens to this lamp. I recommend it to anyone who has the appropriate block. I have an Optoma GT700 (which I also bought from Revain).