Check the listing for details. SUN ST-90 OCCUPANCY COUNTING SWITCH. Condition: New. Listed at 40.00 USD. BRAND NEW IN BOX ~ Sold online for $87.50 Unique sensors can tell who's coming and going The Sun9™ Occupancy Counting Switch utilizes sensors installed in the entrance/exit of any multi-purpose room by counting the number of occupants entering the room and turning on the lamp and ventilation fan accordingly. When all occupants exit the room, connected lights and fans automatically turn off. Detailed Product Features Utilizes a maximum performance 32-bit microprocessor and sensors capable of handling small movement for precise functionality Counts the number of occupants entering and exiting a room Uses standard line voltage to control two separate circuits Supplies low-voltage to sensors through plug-and-play wire (included) Simply replace the existing wired light and fan switch(s) with the single unit. Note: If replacing 2 single switches in a double gang box you will need to special order a single cover plate for a double gang box