Using this Lezyne Femto USB rear cycling light is easy. First, use the versatile mounting strap to attach it to your bike post. Make sure it's firmly in place. To turn it on, simply press the button to cycle through the five output modes. When it's time to recharge, connect the included Micro USB cable to the port, which is protected by the secure cover. As for maintenance, keep the light clean by wiping it with a soft cloth. Avoid exposing it to extreme temperatures. Since it has an IPX7 water - resistance rating, it can handle light rain, but don't submerge it for long periods. Also, check the mounting strap regularly for signs of wear and tear to ensure the light stays securely attached to your bike.