Resonance Frequency Hz: 320 ± 20 % Response Frequency Hz: f¬0 ~ 5000 Impedance (at 1 KHz) : 8 ± 15 % Sound output (600, 800, 1000, 1200 Hz in Average) dB: 88 ± 3 Rated / Max. Power W: 0.25 / 0.5 Buzzer & Rattles (Must be normal) : 2V Sine Wave Distortion (0.25W, 1kHz) : 7% Max. Operating Temperature ºC: -30 ~ +70 Storage Temperature ºC: -40 ~ +85 Diaphragm Material: Paper Cone Terminal : Plate Housing Material : Metal.