W-5 Group Blower Fan with Motor. A failing or bad blower system will show up as fireplace shut down usually on HIGH HEAT. With the high output of air through this unit, when airflow falls short, the element overheats and shuts down the power. Vibration noise, or a raspy rattle is also an indicator that the bearings are worn. Mounting holes are a perfect match for installing screws compared to cheap after market knock offs. 2 wire install is fairly quick. We ship only in Heavy Duty packaging to insure quality And perfect balance of product Shop time 1 hour. updated 12/11/19 dda