RFI Commercial 16378 BTU 240 Volt 4800 Watt 3600 Watt Fan Forced Electric Heater Commercial Grade Vinyl 2641 20: 6 setting maximum speed dial 2641 20: 6 setting maximum speed dial optimizes flow rate from 0 IPM to 21 IPM (inches per minute) based on application a pre wired condor starter and pressure switch combo the recess box (sold separately) is designed for recessing into either frame or masonry walls or ceilings and contains knockouts for wiring connections 240 Volt and 277 Volt units have a standard double pole built in thermostat with provision for a remote wall stat if required 347 Volt and 600 Volt units have a built in thermostat