15.75″x8.5″x2.5″, I had 2 of them over a 5x2x2 tank. Switched to a longer led to get better coverage in the middle and edges. You can find pics of it over the tank on this thread. http://www.reeffrontiers.com/threads/66372-my-150g-build
This is the programmable versions, control all channels at 30 or 60 min intervals. Shoot me offers......If no one is interested guess I might have to switch out the t5 on my 50 gal.