FEATURES- PCvoiceLINK- Silver, Retail pack, clamshell with backerboard
       The PCvoiceLINK, AC-400 R, is a stereo headset microphone. This 
        amplified microphone element can be used for speech recognition 
        applications and voice over the Internet.
       The AC 400 speech recognition headset provides stereo sound and is 
        now Dragon NaturallySpeaking certified.
* Amplified noise canceling microphone element
* Stereo headset (can be worn on the right or left side)
* Deluxe leatherette ear pads
* Adjustable headband and swivel design
* Flexible mic arm
* 7 foot shielded cord
* 3.5mm nickel plated plug
 
 -- SPECIFICATIONs --------------------------------------
DRIVERS           - 27mm dynamic drivers  
CONNECTORs        - 3.5mm gold plated plugs 
MICROPHONE        - output       : -67dBV/microbar, -47dBV/pascal +/- 4dB
                    power voltage: 1.5v to 10v
IMPEDANCE         - Headphone    : 32 ohms
                    Microphone   : 680 ohms 
FREQUENCY RESPONSE- Headset      :  20 ~ 20,000 Hz
                    Microphone   : 100 ~ 16,000 Hz 

Silver. Retail Packaging, clamshell with backerboard- The PCvoiceLINK, AC-401 is a stereo headset/microphone with an in-line adjustable volume control. This amplified microphone element can be used for speech recognition and VoIP applications. Leatherette earpads and ambidextrous design.