The BLK-4 provides high visibility indication of analog line status through a high powered 360º LED strobe and/or beacon visual indicator. The BLK-4 is the ideal solution for the hearing impaired and can be used equally well in loud warehouses or factories, where ringing phones can not be heard. Alternatively, the BLK-4 can be used to add emergency notification to pre-existing emergency phones by turning on the strobe light when the emergency phone is in use. The included control module has a disable input which is ideal for two-button emergency phones, such as Viking’s E-1600-20A, allowing “Info” button calls to be placed without activating the relay (turning on the emergency strobe light, camera, etc.) Four DIP switches are provided for turning ring detection on or off, off-hook/loop detection on or off, 12VDC or dry relay contact output and for selecting a ring cadence mode which allows the relay to follow ringing or to remain activated during the off time of standard ring cadence. The control module can be installed on any standard telephone line or analog PABX/KSU station. The strobe can be interfaced to flash on ringing, off-hook or a combination of ringing and off-hook (line in-use). The BLK-4 is designed for indoor applications. The BLK- 4-EWP is equipped with Enhanced Weather Protection (EWP) for outdoor installations where the unit is exposed to precipitation or condensation. For more information, see DOD# 859. The kit includes: (1) control module, (1) SL-2/SL-2-EWP blue LED strobe light, (1) 12V DC power adapter, (16) gelfilled butt connectors and (1) single gang weatherproof mounting box with gaskets and hardware.