I used 2 "300w " lights in a 4x4. Here's the before and after pics. You can search the specs and details if needed. For 200$ (99$ a piece), I give er a thumbs up. Are they amazing? No. But they grow a plant. Before: After about 75 days (one 24w bulb in the middle to add more red to the runt, disregard it) After about 85 days, the runt was harvested: = Hope this helps, cheers.