The VSA series is a self-contained sound detection system listed by Underwriters
Laboratories, Inc. for the primary protection of reverberant and non-reverberant
vaults, such as bank and mercantile vaults. The VSA-2K is a kit consisting of
one (1) VSA-1 Controller/ Microphone, one (1) VSM microphone, and one (1) RTA
remote test annunciator. Coverage can be expanded by adding eight (8) additional
VSM microphones for a total of ten (10) microphones, including the VSA-1 control
unit/ microphone.