Part #wb38X10005, Microwave Cooling Fan Blade / 8.00 x 7.50 x 1.00. This cooling fan blade (part number WB38X10005) is for microwaves. Cooling fan blade WB38X10005 attaches to the shaft of the cooling fan motor and rotates to blow air over the magnetron. Because high-voltage capacitors in a microwave can retain a let... - Part #wb38X10005, Microwave Cooling Fan Blade / 8.00 x 7.50 x 1.00.