My top 2. cree cxb35xx cob models'. Stupid efficient when potentiometer is used to dim 2x 50w cobs on diff passive heat sinks.. furnished by @Timbergrowlights - dan was a champion. "Plug n play -diy COB lighting" diy for dummies. All color coded n solderless.. jus quick wiring into cobs n mounted driver like so. One simple. Light unit n of course @PlatinumLED GREAT LIGHTS good deal, great customer service. Wana give mars' epistar version a go the price is unbeatable