Specifications:Material: 304 stainless steelModel: Flat Head Hex SocketWeight: 238gSize and Quantity:M4*8mm 20PCSM4*10mm 20PCSM4*12mm 20PCSM4*16mm 20PCSM4*20mm 20PCSM4*25mm 20PCSM4 Nuts 60PCS Features: Designed with 304 stainless steel material, providing strength and offers good corrosion resistance in many environments. Fixing component, for industrial and construction fasteners. Widely used in energy, electronics, electrical appliances, machinery, chemical industry, metallurgy, mold, hydraulic, and so on. This item kit includes M4 hex socket flat head screw bolts and hex nuts, is a ideal combination. This bolts screws and nuts come with a plastic box, so is convenient to storage.