Air cleaner thermostat question

The two nipples of the thermostat that stick out the bottom of the air cleaner have a speed nut of some kind on each nipple. I recently bought a new thermostat. I had to break those two nuts to get the old one out. Does anyone know what those nuts are called and/or where to find new ones? Below is an ebay auction that shows the nuts with the thermostat. Thanks

[ame="http://www.ebay.com/itm/221524977652?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT"]http://www.ebay.com/itm/221524977652?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT[/ame]