describe 100% brand new and high quality. Easy to use and carry, low power consumption, super loud alarm. Simple and effective personal safety device. It is suitable for night shift workers, ladies, the elderly, the disabled, joggers and people traveling alone. In case of danger, simply pull out the latch on the keychain to trigger the alarm, and the alarm will emit a super loud alarm sound. When the loudness of the siren decreases, unscrew the battery cover on the back of the siren and replace it with a new battery of the same type. Item type: Alarm keychain Material: ABS plastic + metal rod Size (length * width * height): about 6cm x 4.5cm x 2cm Loudness: 120 decibels Battery: 12v23A (replaceable) (not included) Working voltage: 5V Color: pink, blue, yellow, back Quantity: 1