Using the Request for Quote (RFQ) form provided on this page, you can request competitive procurement options on part number 121-7637 with rapid responses always offered by our staff. To ensure that you locate and procure exactly what you need with ease, we list parts with as much information as we can. For example, part number 121-7637 It is listed as Back Up Ring Preformed Packing. component manufactured by Perkins Engines Co Ltd, specifically under CAGE Code K2709. It is also accompanied by the NSN 5330015462834 for ease of organization, the first digits of the NSN indicating that the part belongs to FSC 5330 Packing and Gasket Materials.