This item is a Sonet QT™ 4-Pack that includes 1 Controller, 4 Emitters, power supply, connecting cables and mounting hardware. All components are plug-and-play. For best results, install one Sonet QT™ base system for each cubicle workstation, small room up to 200 square feet in size or 20-30 feet of hallway. Choose the Sonet QT™ 4-Pack to treat offices up to 400 square feet or 40-60 feet of hallway. For complete information on Sonet QT™ see below:.