Use on cars.Color:Bronze ToneThread Inner Diameter: 8mm/ 0.31inches Head Inner Diameter: 9mm/ 0.35inches Head Thickness: 1.5mm/ 0.06inches Outer Knurling Size: 11 x 9mm/ 0.43 x 0.35inches(D*L) A Rivet Nut fastener is a tubular rivet with internal threads. It can be installed in seconds form one side of the work. Once installed, no finishing work is required on the Rivet Nut fastener. The added benefit of not only being a fastener, they are ready to use with clean threads available for screw attachments.Blind materials that are too thin for a tapped thread. Blind Rivet Nuts also when an application has little or no access to the backside as they can be installed from the front side of the work piece.Package Includes:50(+/-2%) x Rivet Nut