Two groups 3-color red/green/yellow lights. Lights include red, green and bulbs. Prewired quality products. Black wire is for positive, the other three are for negative. Each line corresponds to the color of the glowing colors, the green line is the green LED, the is the red LED, the yellow line is the yellow LED. You can also connect with 5V transformer without circuit board, black wire with positive, and the other three with negative. Great accessories for , buildings, models. Colour:black Material:plastic+metal Size:7*8*0.5cm Package Contents: 1* lights 1* control panel Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.