Uxcell 100Pcs Rivet Nuts Carbon Steel Rivnut M3 M4 M5 Zinc-Plated Knurled Flat Head Threaded Insert Nut for Screw Attachments Specification: Material: Carbon Steel Finish: Black Zinc-Plated Thread Size: M3 x 0.5mm; M4 x 0.7mm; M5 x 0.8mm Drill Hole Size (+/-0.1): 5mm; 6mm; 7mm Total Size(L*Max.D): 10mm x 8mm/ 11mm x 9mm / 13mm x 10mm Package Content: 100xRivet Nuts Feature: A Rivet Nut fastener is a tubular rivet with internal threads. The material is too thin to machine the thread. It requires a tool or device to install in seconds from one side of the work. The added benefit of not only being a dependable fastener, but they are also ready to use with clean threads available for screw attachments. Rivet Nuts also are used when an application has little or no access to the backside as they can be installed from the front side of the workpiece. _x000D_