Description Literature Description Freudenberg Sealing Technologies (formerly Tobul) anti extrusion ring, carbon steel, Buna-N, 2.5-15 Gallon, provides a high level of seal performance preventing extrusion of material at high pressures. The positioning avoids any direct contact between the o-ring and the housing walls. State of California Proposition 65 WARNINGCancer and Reproductive Harm - www.P65Warnings.ca.gov. Literature & Docs Accessories