Brake Sensing Instant Highlight – Detects braking and boosts to maximum brightness for about 1 second to alert vehicles behind. Smart Power Saving – Automatically enters sleep mode after 30 seconds of no movement and wakes with vibration or touch. USB C Fast Charging – Built in 300mAh rechargeable battery charges fully in about 2 hours. Four Lighting Modes – Steady, fast flash, slow flash and breathing mode with simple one button control. Compact and Weather Ready – ABS housing with sealed waterproof design and quick strap seatpost mount for easy installation on most bikes. Specifications Material: ABS housing and LED Battery Capacity: 300mAh rechargeable Charging Port and Time: USB Type C, approx. 2 hours full charge Lighting Modes: Steady, fast flash, slow flash, breathing Smart Functions: Brake sensing boost 1s, auto sleep 30s, motion wake Dimensions: 40 × 40 × 20 mm Weight: 30.5 g Mounting: Seatpost strap mount tool free Water Resistance: Waterproof all weather use