Items Description :2/5/10pcsHigh Quality Hex Socket Spring Ball Set ScrewMaterial:stainless steel / 12.9 grade steelSize: d(thread diameter) x L(total length)Metric thread diameter: M3 M4 M5 M6 M8 M10 M12Length: 6mm 8mm 10mm 12mm 16mm 20mm 25mm 30mm 40mmApplications: Machinery and equipment, electronic equipment, communications equipment, hardware lighting, building bridges, furniture decoration, etc.Questions you may be concerned about:1.Wholesalers and retailersFor wholesale,we will offer discount or free express shipping .If you are a retailer, we could send the goods to your customers directly ,and won't leave information about us .Please contact us to get the service you need2.If you don't receive you itemPlease contact us first, we will track your item. If you can't receive it, we will full refund or resend it for.3.If you have questions about the productPlease contact with us in time, we will help you solve it.