As an additional safety light such as the bicycle itself, complete with bicycle helmet, dog collar or leash. Very easy to install and remove. The light is splash-proof. The light colors red, green or blue (RGB) can not be selected. Press 1x: flashing light (RGB light up simultaneously, looks like blue light) Press 2x: RGB color change Press 3x: from The first winter have survived the skulls mühlelos. Cheap recommendable product! 1 star deduction because neither color nor permanent light can be adjusted. Conclusion: 4 stars