The Hillman Group 44227 1/2-20 Thin Pattern Nylon Insert Stop Nut， Zinc， 12-Pack<div style="text-align: left;"><strong>[Product Information]</strong><br><ul><li>Nylon Insert Stop Nuts have a captive undersized nylon washer that creates friction with the mating threads to prevent loosening</li><li>Helps resist the effects of vibration and other forces</li><li>Thin pattern</li></ul></div><img src="http://ecx.images-amazon.com/images/I/41d8VM1iG3L.jpg" noproxy>