Not sure what these are called, but I made some last night. Pretty cheap to make and they work great. I've looked around in parts stores but couldn't find anything. Sorry about the last pic being a little blurry. Basically I bought some M8x1.25 hex bolts, a few nuts, lock washer & flat washers & a rubber stopper. Drill a small starter hole thru the stopper. Then drill thru with a 3/8" bit. Then counterbore half way thru the stopper with a 1/2" bit. Insert the hex bolt w/lock washer into the counterbore and tighten up. Works great and easy to adjust.