Industrial Covert Unlimited is in its 20th year of operation. CU1.COM has been up since mid 1999. Great security & CCTV products and people who answer the phone!
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ETS SM3 One Way Listen Only Monitoring Base Station W/ Volume Control
The ETS SM3 is a stand alone base station for monitoring any SM1 series microphone. It has terminals for connecting and powering up any Sound Surveillance SM1 series microphone, and it connects to DVRs or tape recorders for live monitoring or playback. Additionally the SM3 has a headphone jack for private listening.