STEINEL™ presence detectors with Zum® Link wired communication are part of a system designed to provide sophisticated lighting control with simple installation. A wired solution for Zum commercial lighting systems, the Zum Link Presence Detectors communicate via CBL-CAT5E-ZUMLINK-P cable (sold separately) which allow for in-room device daisy-chaining to other Zum Link devices (such as the ZUMLINK-KP keypad or Zum Link load controllers). The presence detectors are equipped with daylighting capabilities to adjust the lighting based on natural light. The RLY presence detectors also have a three-wire output relay to connect to a relay-input capable device, such s an HVAC call system. The presence detectors mount directly to the ceiling or via a junction box (not included).