Viking Door Entry Control For Viking Door Entry Control For 4 Entry Phones Provides Co Sharing Call Waiting And One Aux Contact Allows An Entry Phone To Share A Single Telephone Line With A Residential Or Business Telephone System House Phones Ring With C.o. Line Cadence Or Distinctive Ring When The Entry Phone Ecalle Button Is Pressed Compatible With These Viking Entry Phones: E10 E20a E30 E40 Handsfree Phones K15007 Stainless Steel Panel Phone Or Use With Any Analog Touch Tone Phone Provide Entry Phone Activated Chimes And Whole House Paging When Used With Viking Model Slp1 Produces Double Ecall Waitinge Tones One Set Of Normally Open And Normally Closed Contacts Available For Operating A Doorbell Camera Lights Etc. Add Door Strike Capability With The Viking Model Rc2a Remote Touch Tone Controller Brand: Viking Electronics