What everyone wants to know, 4x Bridgelux BXRC-35E10K0-L-23's 3500 spectrum wired to HLG-320H-C2100A(the a specifically for the built in dimmer to dim and start on smaller veg plants) and mounted using rails where the COBs can freefloat move them along the railing as needed to direct your light as optimally as possible. For the frame i used 4x pieces of cut down to 2ft pieces, x4 2ft pieces for the outer frame, and then 4 pieces for the inner frame for the cobs/heatsinks to lay on. so basically the LED can freefloat along the rails for more spread out light or direct light+, i Also wrote a guide that you can follow along to make it. philsdabcornerCOMphils-diy-led-growlight if you have any questions PM me here or my email and i absolutely love helping people save money, things are so expensive now