Operating Temp.: -20°C±2°C ~ 50°C±2°C Approx. Weight: 200g Size: 87.0 x 65.0mm Sensitivity: -159dBm above TTFF : 28 seconds in open sky Speaker Dimension: Φ40mm Impedance: 8Ω±15% Frequency: 680Hz ~ 20KHz Rate Power: 1W Max 2W Decibel: 92dB±3dB Type: Dynamic Microphone Dimension: Φ6.0 x 5.0mm Impedance: 2.2kΩ±10% Sensitivity: -44dB±3dB Frequency: 50Hz ~ 15KHz Pattern: Omni-directional Patent Number US Patent:: 7,668,566/7,783,298/6,912,397/6,941,147 Taiwan Patent: M338507/M350183/M315917/I252705/I 248771 China Patent: ZL 200720139535/ZL200620120732/ZL200620118447X ZL2003201299906