Using the Request for Quote (RFQ) form provided on this page, you can request competitive procurement options on part number 57421-21 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 57421-21 It is listed as Grommet. component manufactured by L 3 Communications, specifically under CAGE Code 11447. It is also accompanied by the NSN 5325000078070 for ease of organization, the first digits of the NSN indicating that the part belongs to FSC 5325 Fastening Devices.