Not familiar with them either, however as Jake mentioned for seasoned hay, oats, corn stalks, 99% of this was left uncovered. Just put in rows with bales butted up to each other. In west central Illinois, I think most farmers on tight enough budget and didn't see much difference with product versus time and money invested. Also, the guys that I custom hay baled for knew what they wanted for winter bale numbers and if they had extra over that...it would be sold. Most never had anything to old that they would be feeding then either.