The C-4000 converts any four touch tone phones into multi-number auto dialers that will store up to 250 telephone numbers in non-volatile memory. Use with Viking's K-1700-3 or K-1900-8 phones to provide vandal resistant handsfree or handset communication from entry points to apartments or offices.

When a call initiated by the C-4000 is answered by an apartment or business tenant, a built-in contact closure may be activated by touch tones to control an electric gate or door strike. Up to 250 entry codes may also be programmed providing tenants with keyless entry or optional Viking proximity readers may be added for card / fob entry.

The C-4000 can be programmed locally or remotely using a standard Touch Tone phone. The C-4000 has built-in user dialing restriction to help prevent unauthorized calls and toll fraud.