Staying-Fit Red LED Bike Tail Light, Sealed USB Rechargeable. 4 Flashing Light Safety Modes -BE SEEN WHEN YOU NEED TO BE SEEN. Introducing the RAPID-X Bike Tail light. RAPID-X features 5 LED that provide 180 degrees of viability. Simple to install on your seat post or anywhere that offers rear viability. -BRIGHT LIGHT KEEPS YOU VISIBLE - The 180 degree illumination design provides excellent rear and side visibility. Other Tail Light only offer rear visibility! Practical, Reliable, and Durable. Built to perform. LED lights are Sealed for water protection. -USB RECHARGEABLE - The RAPID-X Lithium Rechargeable Battery charges from your computer or any device via a USB port with the included USB cable. 2 hours to fully charge. 4 Flash Modes: Shun Flash (12hrs run time), Slow Flash (10hrs run time), Strobe (8hr run time) , Long Bright (4hrs run time). -ENVIRONMENTALLY FRIENDLY - Environmentally friendly materials used, non-harmful substances such as lead and mercury -STREAMLINE DESGN - Won't catch your gear, clean fit