Serfas Seat Stay Taillight The industry's most technologically advanced safety lights All lights are robs compliant and all testing is done in house More efficient leds & high quality lenses to increase brightness & Clarity One 1/2 Watt Center LED and 6 additional LED's for maximum visibility Latest generation Serfas seat stay taillight Water resistant silicone body and straps Removable/Replaceable Silicone Mounting Straps Mounts to any tube on your bike More water resistant Silicone casing, "Version 2.0" of our famous TL-ST, Upgraded design with better built body, Features removeable straps, Bright Light Output, Comes in 8 different colors.