The Smart LED Emergency Bulb works like a normal bulb and uses an everyday light switch but when the power goes out, it continues to light up. It uses its rechargeable battery when electricity fails. After a power failure, the bulb will stay on for four hoursand it can be used almost anywhere.
Finger touch type and portable.
When there is electricity in your socket, it is a normal LED bulb, when blackout, it will be an emergency bulb keep working.