Containing both a 24VDC supply and a 20A line voltage relay for most models, the Leviton compact power pack provides low voltage power and line voltage control for Leviton Occupancy Sensors. Versions include Auto-ON and Manual-ON inputs for occupancy sensors, Hold-ON and Hold-OFF capabilities, and a local input for momentary or maintained dry contact switches. The internal relay can control up to 20A for a 120, 230, 277VAC or 347V ballast load and 20A for a 120VAC incandescent load. The OSP Power Pack Series is also used to supply power to the OSA Add-A-Relay model. The Power Pack conveniently mounts in a knockout hole of a standard junction box. The unit can be placed inside or outside the junction box with a simple twist-on nut. 15A INC 20A FL 120/277VAC 15A FL 347VAC, Add-A-Relay for Occupancy Sensor with HVAC Relay 0.5A 125VAC 1.0A 30VDC, Made in USA.