They are basically spacers that snap around the trim cylinder shaft. they are built for limiting the amount you can retract the shaft. We use them on the brush hog so we can just put the lever down all the way without running the blades in the ground. I have to pull my boat 2.5 hrs so I always use them so the trim isn't under pressure. I also have big rubber washers I put above and below to add some cushin to it. (actually the washers are old cut up crocs). I borrowed this pic from Tractor Supply. I got the idea from the m-ywedge thing they sell for outboards.
