Links to directly to Intercall Nurse 600 / Intercall 700 Call Systems and most other Nursecall systems with a mono plug. INTERCALL NURSECALL 600 /. INTERCALL NURSECALL 700. PRESSCALL PC1. FOR USE ON INTERCALL NURSE CALL SYSTEMS OR ANY OTHER COMPATIBLE SYSTEM WITH A MONO JACK PLUG THAT OPERATES WITH A CLOSED SWITCH WHEN THE BULB / BUTTON IS PRESSED.