Rated voltage(V) 1.5 3 Operating voltafe(V) 1~2 2~6 Rated current(mA) ≤30 Coil restance(Ω) 16 45 Coil restance(Ω) 40 120 Sound output at 10cm(dB) ≥85 Resonant Frequency(Hz) 2400(2000,4000) Operating Temperature(℃) -20~+70 Storage Temperature(℃) -30~+80 Weight(g) 2