Suncourt TW208P Thru Wall Fan Hardwired Variable Speed EQUALIZE TEMPERATURE - Used in conjunction with PTAC units, mini-splits, fireplaces, wood stoves, window air conditioning units and other HVAC systems QUIET OPERATION - The sound levels are 55dBA on high speed and 49dBA at low speed, this compares to the sound of a desktop computer fan VARIABLE SPEED - The ThruWall Pro has a variable speed dial that lets you control how powerful to make the airflow COMFORT - Balance temperature between rooms, with the rotatable grille you can direct airflow to your preference HARDWIRED - Requires direct installation into the homes electricity. The telescoping housing allows wall widths from: 4"-6.5" thick