Automatic light turn-on when braking, clearly visible light, mini and rain-resistant design, replaceable battery make this product a long-term companion for your cable actuated mechanical brake. <br><br><strong>Features:</strong><br> Automatically turn on when you brake, otherwise it will turn off.<br> LED brake light powered by replaceable AG10 battery for practical use.<br> Clearly visible light offers you a safer night cycling. <br> Rain-resistant housing allow it to work on a rain day.<br> Used for all cable actuated mechanical brakes.<br> One flat and smooth screw end to protect the brake cable.<br> Installed only with a 2.5mm hex wrench provided. <br><br><strong>Specifications:</strong><br> Color: Red <br> Material: ABS<br> Battery: 1 * AG10 (Included)<br> Item size: 30 * 30mm / 1.2 * 1.2in<br> Item weight: 7.6g / 0.26oz<br> Package size: 9.7 * 6.4 * 2.3cm / 3.8 * 2.5 * 0.9in<br> Package weight: 19.3 / 0.68oz<br><br><strong>Package List:</strong><br> 1 * Brake Light