Rated voltage(V) 1.5 3 5 Operating voltafe(V) 1~2 2~4 4~7 Rated current(mA) ≤70 Coil restance(Ω) 6.5 16 45 Coil restance(Ω) 16 45 110 Sound output at 10cm(dB) ≥85 Resonant Frequency(Hz) 2731(2000) Operating Temperature(℃) -20~+70 Storage Temperature(℃) -30~+80 Weight(g) 1