Details: *High energy and hardness.*Not clean to rust.*Convenient to use.*Material: carbon steel*Color: Black* treatment: galvanized*Size: 6mm/7mm/8mm (As photo show)*Quantity:10pcsPackage Contents:10pcs*ScrewNote:1.The genuine colour of the item could also be slightly varied from the images proven on website brought on by many points comparable to brightness of your computer screen and lightweight brightness.2.Please enable slight guide dimension deviation for the data.