This LED bulb has build-in recognize circuit. It will automatically light up when the power supply suddenly breaks off. It supports long-time lighting for emergency. It can be used as emergency light just by making current circuit such as taking the bulb head by thumb and middle finger and touch the bulb top by index finger. Specification: Color temperature: 6000K Input voltage: AC 85-265V Current: 3A Charging time: 1-2H Material: ABS Item size: 7.8 * 13.3 cm / 3.1 * 5.2 in (D * H) Item weight: 105 g / 3.7 oz Package size: 12.8 * 8.5 * 8.5 cm / 5 * 3.3 * 3.3 in (L * W * H) Total weight: 140 g / 4.9 oz Package list: 1 * LED bulb