Using the Asteroid bike tail light is a breeze. To turn it on, just double - click the lens. To switch between its 3 modes - Flash, Pulse, and Steady - single - click the lens. When you turn it off and then back on later, it will start in the same mode as before. You can ride for up to 24 hours before you need to recharge it. Use the included micro USB charger to recharge it. This tail light is weatherproof, so it can be used in any season. But still, try to avoid submerging it in water for a long time. For maintenance, keep the lens clean with a soft, dry cloth. Don't use harsh chemicals. The light comes with a lifetime PD Warranty, so if you have any problems, you're covered.