... (square, rectangle)5 Dimmable optional6 High quality light source. The attenuation of SMD LED light source is less than 3% by 3,000hrs ... : 1.Round panel: Power: 8W, 10W, 12W, 16W, 20W,25W,36W,40W Size: D155*18mm, D180*18mm, D210*18mm, D255*18mm ... , D300*18mm 2.Square panel: Power: 18W, 36W, 25W, 40W, 58W Size: 300*300mm, 600*600mm, 600*1200mm ...