product description;1.USB rechargeable battery: The personal alarm siren is made of rechargeable lithium battery, not a button battery. No need to replace the battery, just use the USB cable to charge.2. Security emergency alarm: With ear piercing sound, it can also attract the attention of others from 300 yards away when you are in danger. Continuous sound ensures emergency use. It will replace self-defense weapons and keep you safe because pepper spray3.2 ways to use: You can quickly pull the contact pin out or press the switch 2 times to activate the alarm.4. LED emergency flashlight: The bulb is bigger and brighter than traditional security alarm lights5. Lightweight and Portable Alarm Clock Keychain: The self-defense alarm clock can be mounted on wallets, backpacks, keys, belt loops, suitcases. It can also be taken on the plane, very convenient, suitable for students, joggers, elderly, children, women, night workers.