ELK Elk 930 Doorbell and Phone Ring Detector

See When Your Phone or Doorbell Rings!: Detects Doorbell Activation Current; Inputs for Two Separate Pushbutton Locations; No Interference With Lighted Pushbuttons; Produces an Open Collector Output; Powered by the Doorbell Transformer; Detects Telephone Ringing Voltage; Provides an Open Collector Output that follows the ringing pattern; Small, Compact Size; Double Sided Foam Tape Provided For Mounting; Packaged in Reusable Poly Storage Box; Lifetime Limited Warranty