Type SFM27-W V.Rated Voltage 12 V.Opcration Voltage 3~24 mA.Rated Current ≤12 dB.Soud Output ≥95 Hz.Resonant Freq 3000±500 Operating Temp -20~+60 Storage Temp -30~+70 g .Weight 7 R/SFM-27-W is the specifications for this type of ROHS products .W means black box.