【SMART BRAKE SENSING TECHNOLOGY】- This smart bike rear light instantly detects braking actions, triggering a 20% brightness boost in steady-on mode for 5 seconds to alert following vehicles—reducing rear-end collision risks during night rides; Perfect for urban commuting and road cycling, the intelligent brake response ensures maximum visibility when you need it most 【4 ADJUSTABLE LIGHTING MODES】- Bike tail light choose between Steady On, Fast Flash, Slow Flash, and Breathing Flash modes to suit different riding environments; Long-press 2 seconds to power on, then single-click to switch modes effortlessly, providing optimal visibility in daylight or low-light conditions while catering to your personal preference 【VIBRATION SENSING AUTO WAKE-UP】- CYCLAMI bicycle tail light features automatic sleep mode after 30 seconds of inactivity and 30-minute auto-shutdown to conserve battery; A gentle vibration wakes the light instantly, resuming the last used mode—no need to reset settings. Ideal for frequent riders, this smart function ensures hassle-free operation and extends battery life 【WATERPROOF & ULTRA-COMPACT】- This bike rear light built to withstand rain, splashes, and harsh weather, the IPX6 waterproof rating guarantees reliable performance in all conditions; Weighing just 0.85oz with a tiny 1.54×1.54×0.98 inch size, it’s lightweight and portable, easily attaching to any bike seat post without adding bulk—perfect for on-the-go cyclists 【LONG-LASTING BATTERY】- Powered by a 500mAh 3.7V battery, enjoy up to 3.5 hours of steady light or 6+ hours in flash modes; The modern Type-C port allows quick recharging, ensuring your smart bike brake tail light is always ready for night rides. Lightweight design meets long battery life for unmatched convenience 【SMART BRAKE SENSING TECHNOLOGY】- This smart bike rear light instantly detects braking actions, triggering a 20% brightness boost in steady-on mode for 5 seconds to alert following vehicles—reducing rear-end collision risks during night rides; Perfect for urban commuting and road cycling, the intelligent brake response ensures maximum visibility when you need it most