... Pinhole Style Microphone,Omni Directional, Monitor Range 10-30sq.m,Size 60mm*22mm, Weight 30g, White / Black CasePart of customers ... loading protection and lightning proof circuit.*Pre-amplifier, directly drive DVR, VCR, headphone, loudspeaker etc.*Excellent voice experience, widely ... s Material PVCSize 60mm × 22mmWeight 30gStandard CE I.TRADIO hidden,mini,built-in wall Audio Surveillance Microphone