This is plastic insert that lets self-tapping trim screws easily thread into sheet metal panels. It snaps into a square hole 10mm wide and anywhere from 12mm to 20mm long. It is intended to be a drop-in replacement for (and thus is closely modeled after) Honda p/n 91517-SH3-003, which is used on 1991 model year (and possibly '88-90 as well) Civic hatchback, sedan and CRX models to attach the trim panel at the base of the windshield. I'm sure this seems like the most random part to upload, but I whipped up this substitute after getting frustrated with the old stripped-out, disintegrating parts on my car and thought I would share. The other option would have been to drop $25 and wait a week or two for OEM parts to arrive. That is, assuming they're still available.