Just finished this LED diffusion head for my Omega D2 enlarger. It entirely replaces the condenser head so you have to use under-the-lens filters. It works pretty well - the light is even and the multi-contrast filters work as expected. I used six Cree XP-E's at 1 ampere which generates about 900 lumens but the white acrylic soaks up about half that so only about 500 lumens hits the negative. The major thing that is not ideal is that the 24 volt power supply takes about 1.9 seconds to come on after plugging it in. The light doesn't ramp up; it just snaps on at full brightness after 1.9 seconds. I've dealt with it by simply adding 2 seconds to the time on the Gra-Lab but it would be nice if that were not necessary. Testing with a step wedge shows contrast is about the same as the condenser head which is surprising - I expected it to be softer. That may be a consequence of the spectrum of these LED's which are a little cooler than an incandescent bulb. The Cree LED's I'm using have a listed color temperature of 3000K. Overall I'm very happy with it and I can't wait to try it out on some real pictures.