Product Name : Active Electronic Alarm Buzzer;Rated Voltage : DC 3-12V;Resonance Frequency : 2.8 ± 0.5KHz Sound Pressure : >= 85dB/10cm/5VDC，Operating Temperature Range : -20-+70C Body Size : 12 x 9mm / 0.47" x 0.35" (D*H);Wire Length : 5cm/2" External Material : Plastic;Color : Black Weight : 28g;Package Content : 15PCS x Active Electronic Alarm Buzzer Plastic housing, DC3-12V rated voltage, 2 wired connctor, convenient for connecting. They have good characters like small cubage, low wastage and high voice pressure.