Compatible with Viking's vandal resistant K 1700 3, K 1900 8, or any Touch Tone phone Non volatile E2 memory no batteries required Remotely or locally programmable Stores 250 tenant Touch Tone phone numbers and keyless entry codes Programmable tenant's relay activation code Programmable master keyless entry code and five maintenance codes Programmable call timer Multi number dialer mode for Kiosks, etc. Ring thru mode for calling the entry phone Normally open and normally closed DPDT relay contacts for controlling door strikes, magnetic locks, gates, etc. Auxiliary relay input to trigger a timed relay activation for postal locks, etc. Touch Tone and pulse dialing toll restriction Programmable allow/restrict for 911 and 311 outside calls Log bus data output for logging entry events