Multiple light modes & Red LED's help to ensure that you are seen when out running or walking in all weather. 3 light modes available; flash, fast flash & constant. Lightweight & Breathable: Designed to be as lightweight as possible using high quality materials to allow use in all temperatures. Adjustable fit to suit virtually all sizes, male and female. Using the adjustable buckles you can get the perfect fit from the elastic straps and the quick release clips help to ensure it is easy to put on and off. Reflective logos and trims give you 360 degree reflectivity to help ensure you are more visible when out on the roads no matter the time of day. Batteries included: Two CR2032 button batteries are included (one for the front and one for the rear lights)