It comes with a CHARGING CABLE that charges from your computer, power bank or any device with a USB port.The bike tail light is IP5 waterproof and dustproof to ensure safe use in rain. It cannot be used underwater.The bicycle light is red & blue, lasting up to 2-4 hours depending on the mode you use. Weather tight design ensures all condition use.75% of bicycle accidents occur during the day, and safety during the day and night is equally important. The rear bike light not only allows you to see it at night, but also during the day, and can be seen by drivers over 1,500 feet away. 4 modes: You can choose the riding mode you like: highlight, fast flashing, warning fast flashing, and warning slow flashing.