DoorKing 1875-010 Phone System Telephone Bypass Switch Doorking Keypad Each master allows for communication

Each master allows for communication with the outside door and door release control

The Ultra is now compatible with the Viking Loop Detector Rack

Built-in reset switch

Single Form C dry contact relay

Cellular Service: 4G-LTE cellular connectivity powered by AT&T (requires DKS Cellular subscription and adapter)

DoorKing 1875-010 Phone System Telephone Bypass Switch Doorking Keypad Each master allows for communicationDoorKing 1875 010 Phone System Bypass Switch Used with DoorKing 1812 phone systems. Can be used with other phone systems such as Sentex Crown Jewel, Liftmaster TAC, Elite EL25, Linear RE and most residential phone systems.