8-342/U - 3-5/8'' ID X 4'' OD X .055'' High Backup Ring (2 Pack): Amazon.com: Industrial & Scientific
Backup ring P28, Teflon SPIRAL Lower electrode Pack of 10 905201420001 | Elemental Microanalysis
Case Study: Benefits of a Contoured Back-Up Ring | Marco Rubber and Plastics
Global O-Ring and Seal on Twitter: "Requesting for backup? We have backup rings readily available in NBR, Viton, and Teflon (Solid, Split, and Spiral versions). Use our Backup Ring Size Chart here
Back-up ring - Anti-extrusion ring - FRANCE JOINT
Back-up Rings for Oil & Gas Applications - Trelleborg