Andrea Electronics C1-1025400-1 model ANC-300L Dual Function Hand-Held Computer Microphone, UPC 752921041296, Andrea ProVoice Solutions Series, Patented Active Noise Cancellation acoustic microphone technology for Speech Dictation, Desktop Stand Operation for Multi-Party Conferencing; 3-Position Selector Switch: Near Field ANC, Mute Switch, Far Field; Compatible with Major Sound Cards, Flexible Shielded Cable, Enable superior microphone performance with desktop speech-enabled applications, Noise Cancellation 6 dB/Octave, Frequency Range 100-10,000 Hz, Impedance at 1 kHz: 300 ohm with SoundBlaster Interface and 650 ohm with Andrea Preferred Interface, Electrical Signal-to-Noise Ratio 60 dB, Sensitivity at 1kHz 0 dB = 1 V/Pa: -36dB with SoundBlaster Interface and -28dB with Andrea Preferred Interface, Current Consumption: 0.500 mA with SoundBlaster interface and 0.800 mA with Andrea Preferred interface, Product shipped by the Manufacturer in a Plastic Bag only (no blister pack or retail box).