Features: 100db-120db alarm sound; plug switch is easy and effective for use. Mini and portable in design then it can be hanged with keys or other personal things, very convenient. Just pull off the hand strap to active the alarm when you are in emergency situations. To turn off the alarm, just insert the hand strap to the plug. Lightweight and durable for a long time, can change battery when the sound goes low. It's great for women, old people, children or night shift workers, etc. Specifications: Color: Yellow; Material: ABS; Volume: 100dB~120dB; Battery: 23mA 12V (not included); Working Distance: Approx. 400m2