These chaser lights can be used to decorate your tree and are suitable for both indoor and outdoor use. Their ultra bright LED lights add a touch of sparkle to your festive display and come with a choice of 8 effects. Choose between Combination, Sequential, Chaser Flashing, Twinkle Flashing, Waves, Slow Glow, Slow Fade and Steady On and ensure a warm festive glow around your home. The LED string lights stretch for 21 metres, and will comfortably cover your Christmas tree, outdoor trees, and other large areas. These outdoor Christmas lights require the transformer and mains power box to remain inside and dry at all times even if the lights are being used to illuminate outdoor spaces.