90A Durometer Urethane Back-Up Rings -014 Dash Size, Per Pack

Urethane models like this one are generally good to 220°F.

Urethane at 90A durometer has enough flex to stretch over an O-ring groove without tearing, and once it seats it pulls back to its molded dimensions pretty cleanly. That recovery is what keeps it snug against the bore wall so it can do its job blocking extrusion. Just make sure the O-ring size matches up, since these back-up rings are sized to correspond directly to standard O-ring dash sizes, and this one is a -014.

The -014 dash size is intended to correspond to the same dash size O-ring, since these back-up ring sizes are matched to O-ring sizes.