This is a thicker version silicone O-ring used on a 1/2 nipple for use with weldless fittings. 13/16" hole fits tightly over 1/2" MPT threaded stainless nipples and creates a tight seal. Made of heat resistant (500 degree max temp) Food Grade Silicone. 13/16" ID X 1-3/16" OD (3/16" Thick).
