Self -Clinching Rivet Nuts:These standoffs, which use the proven self-clinching design, install with a squeeze in punched or drilled round holes and become permanently mounted in the thin sheet.Specification:Size:1/4-20Material: Carbon Steel with Zinc PlatingOuter Diameter(Max): 11.18mm/0.44inch;Outer Diameter(Min): 8.71mm/0.34inch;Mounting Hole Diameter: 8.71mm/0.34inch;Length: 5.59mm/0.22inch;Surface treatment: PassivationPackage Content: 100Pcs x Self -Clinching Nuts