Create a unique and breathtaking synchronized outdoor holiday display with Christmas Chasing Lights from Northern Lights and Trees. Chasing Lights sets feature varying moving light functions. Some very common functions are fading and chasing. More extravagant and less common functions are stepping on and two-channel flashing. These lights usually come in longer sets. This is because to give the chasing effect, bulbs must be arranged in four circuits of 35 (equals 140) or three circuits of 50 (equals 150).