... 3.5M3, M4, M5 Length6~25mm, .312~1.062" Finish zinc, copper, nickel, black, chrome plating, galvanizing, etc.Advantage High ... choose us:1. Over 10 years manufacture experience in hardware.2.Professional research and development team.3. Very competitive ... The whole order is done, thank you!! Certifications show: China zinc plated steel/ stainless steel self clinching standoff fasteners,hex rivet nut