I used this unit a short time for woodworking which I no longer do. It is in excellent condition and the battery takes and holds a strong charge. I would think this would be good for working in any dusty environment such as grain handling but have not used it for such.
785 -seven three eight-zero four nine nine call or text
Pickup or can ship to you in original packaging for $25.00 cost.
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http://www.airwareamerica.com/trend-air/p/6-ear-protector.aspx
https://www.youtube.com/watch?v=H7thRSaiXyE
https://www.youtube.com/watch?v=oFXs9VvPBgo