1、High Brightness LED Lamp Beads: Lens is matched with 24 high brightness LED lamp beads to create high brightness and soft and non glaring lighting effect. 2、Intelligent Precise Brake: Built in high accuracy sensor, with depth algorithm, the taillight can quickly detect even slight brake. 3、Auto Calibration and Self Adaptation: It will automatically calibrate according to the different horizontal angles of the seatpost, and the depth algorithm will identify the up and down slopes and keep the braking accuracy at all times. 4、Manual Smart Mode One Key Switch: Long press to switch the machine, short press to switch the flashing mode, the always on gear is the manual mode, not controlled by the light sensor and riding status, the other five flashing gears are the smart mode. 5、Reduce Rolling and Small Bumps: Optimize the program algorithm to reduce small rolling motions and small bumps. However, the brake light warning will still be activated if the damping belt is too large. 6、Life Waterproof Design: Ride without fear of wind and rain. Waterproof design can prevent rainstorms and avoid long term rain. It can easily cope with daily life and outdoor sports. 7、Power Display Function: Short press the switch in shutdown state, the green indicator light indicates the remaining power. 400mAh battery capacity, USB fast charge, full power in 2 hours and 20 minutes, the brightest battery life is 15 hours, the maximum battery life is 48 hours, and the standby time can be up to one year. 1 x Tail Light1 x Seatpost Mounting Frame1 x Cushion Mounting Frame1 x Silicone Strap1 x Spacer2 x Gasket4 x Cable Tie1 x USB Charging Cable1 x Manual  Item Type: Smart Bicycle Tail LightColor: As Pictures ShownMaterial: ABS+PCSize: Diameter: 35mm/ 1.4inWeight: Approx.73g/ 2.6ozCharging: USB Fast ChargeBattery: Polymer Lithium Battery 400mAh (with Built in Battery)Features: Precise Intelligent Braking, Adaptive Horizontal Angle, Precise Movement Start and Stop, Sensitive Light Start and Stop, Reduce Rocking and Bump, Life Waterproof Design, 48 Hours Long Battery Life, High Brightness Lamp BeadsMultiple Installation Methods: Seatpole Installation and Cushion Installation