The E-40 entry phones can share a single phone line with house or small business telephones when used with a Viking model C-200 or C-2000A Entry Phone controller. The E-40 entry phones can also be connected to an unused analog station port (programmed for ring down) on a phone system or connected directly to a telephone line when used with a Viking model K-1900-5 auto dialer. The E-40 features microphone and speaker volume controls, selectable auto answer for monitoring and intelligent call progress detection for automatic hang-up when the call is completed. For extreme outdoor environments or corrosive atmospheres, the E-40 Series is available with Enhanced Weather Protection (EWP)