we have 30'800 series that we put the raised feather sheets on. when the feeder house plugs and you reverse it the crop would get between the raised and the "old" feather sheets causing the "new" to raise up,so if you lower the head to the ground this wont happen,says our dealer.not true!!however it does help but does not prevent it.a big object ,like a rock,will damage the new sheets.so what we did was cut off the old sheets, leaving enough sheet,in the back, for the new sheets to rest on ,thus preventing any debree from getting inbetween the sheets....it work well for us.the new sheets really helped in short beans andalso helped beans from bunching up on the head when the stems are a little tough{early morning or late night}.