[ ALUMINUM ALLOY SHELL & IPX6 WATERPROOF ] - Made of aluminum alloy shell, this bike rear light has a nice touch and awesome appearance. It's waterproof/dustproof and shockproof, suitable for any harsh working environment. we guarantee a 12-month warranty, 30-day money back and 24/7 customer service to make it no risk for you to purchase this taillight. [ BRIGHTNESS ADJUSTABLE & POWER INDICATOR ] - The brightness of this bike rear light is adjustable, in the steady on mode, just long press the button to adjust the brightness that you need, it Built-in 400mAh Li-ion battery, it can lasting 50 hours (will be influenced by the brightness that you setting) runing time when fully charged. four blue indicator lights, each shows 25% capacity, No longer worry about forget to charge. [ AUTO ON/OFF for BATTERY SAVING ] - This Smart bike tail light including Motion Sensor and Light Sensor, it will be auto off when detect in no motion after 30 secs. Once touch it or detect the bike is moving, the light will auto on again. Also when you ride under the sunlight, the tailight will be auto off due to the light sensor is working, IF YOU LIKE TO RIDE IN THE DAYTIME AND NEED THE TAILLIGHT KEEP WORKING ALL THE TIME, please choose the mode 3 and mode 4 to avoid Light Sensor working. [ FOUR LIGHT MODES & HIGH LUMEN LED ] - There are 4 light modes for your choice, (1)Normal Flash Mode, (2)Breathing Flash Mode, (3)Fast Flash Mode, (4)Steady On Mode, enjoy your cycling as you wish, High lumen COB Led bike taillight makes you more visible, it's a perfect bike light for night riding. [ SMART BRAKE SENSING & EASY to INSTALL ] - Automatically switch to high light mode when braking, ultra-bright for 5 secs lights warning back rider to enhance your safety. You can mount it under the saddle with metal mounting bracket or mount to the seat post with adjustable silicone strap.International Protection Rating: IPX6. Auto Part Position: Rear. Item Dimensions LxWxH: 1.34 x 1.34 x 1.57 inches. Mounting Type: Seat Mount. Item Weight: 3 Ounces. Water Resistance Level: Waterproof. Power Source: Battery Powered. Material: Aluminum. Brand: G Keni. Color: Red. Date First Available: August 8, 2019. Best Sellers Rank: #8,907 in Sports & Outdoors. Customer Reviews: 4.6 out of 5 stars 1,992 ratings 4.6 out of 5 stars. : B07W4PGHK7. Part Number: ?Q5. Manufacturer: ?K&K International Co.,Ltd. Suggested Users: ?mens. Material: ?Aluminum. Color: ?Red. Model Name: ?Q5. Warranty Description: ?1 Year. Brand Name: ?G Keni. Item Weight: ?3 Ounces. Item Dimensions LxWxH: ?1.34 x 1.34 x 1.57 inches. Package Weight: ?0.13 Kilograms. Item Package Dimensions L x W x H: ?4.69 x 3.19 x 1.54 inches.