Fasco W4 115-Volt 3300 RPM Furnace Draft Inducer Blower 3300 RPM, Rotation Counter clockwise Thermally protected UL recognized Genuine Fasco product. 4 studs on front of blower for mounting - 4 3/16 Inch on Center measured diagonally (# 8 threads). 1/20 hp. 6 Prong Female Connector OEM replacement for A.O Smith draft inducer No.7021-10195