Please kindly noted that this item is sold by jindouyunshanghai from Joybuy marketplace.Specification: Material:Carbon Steel Color:Black Quantity:500PCS Feature: -These screws are made of high quality steel, they are very strong and resistant to use. -It is widely used in the industry. -There are different lengths in one set to meet your different needs. Note: -Please allow 1-3mm errors due to manual measurement. -Due to light and screen setting difference, item's color may be slightly different from the pictures. Package Included:(Total:500PCS) 100PCS:M3*6 100PCS:M3*8 100PCS:M3*10 100PCS:M3*12 40PCS: M3*16 30PCS: M3*18 30PCS: M3*20