KSI Supply, Inc. Silage protection is our business. Home Products Contact About us We're a family owned business serving farmers. First with construction in 1965. Then in 1987 and through today, building bunkers. And now since 1992, selling bunker covers. Protecting silage is the only thing we do. KSI Supply, Inc. KSI Supply is your Midwest source for silage protection- bunker covers, oxygen barriers, silage bags, bale wrap, bale net wrap, twine, and tire sidewalls. Call us at 920-467-2454 for exceptional quality, service, and value. We offer personal service no matter what your size. Coast to coast delivery. We will not be undersold. Click here to look at our product selection. We offer hard to find widths in bunker covers including 6 mil 65’ single extruded with no welded seam. That means time and money saved in sizes that fit your needs. Click here to see why oxygen barriers are important! They prevent spoilage and reduce waste. Ask why ours are a better value! Over 39 million square feet sold in 2014! Ask about our high density twine with Ultra Grip for superior knot strength.