ZFE Mixed Pack Threaded Rivet Nut Inserts M4.M5. M6. M8.each 25pcs Total Pack of 100Pcs Product Name : Rivet Nut Size: M4. M5. M6 and M8 100 Mixed Pack(each 25) Material : Carbon Steel,Zinc Plated Type : Flat Application : metal, plastic and fibreglass between 0.5mm and 3mm thick.