Voltage: DC 4~7V; Communication interface: single line; LED drive chip ws2812B integrated LED; 12 PCS high bright smart LED NeoPixels arranged in round 50mm PCB; Those annulus RGB light can be simple connect one input pin to another (DI-->DO) through output pin cascade; Though cascade, just use one pin of singlechip, you can control LED light as many as possible; Each LED integrated by one piece drive chip become smart and addressable; Each LED has 18mAh constant current drive, so the color will be same. Even though voltage changing is the same, no external resistance needed, the current-limiting resistance make RGB integrated design become slim. Use 5V power supply (working current 4~7V) drive RGB lamp ring.