[Material]Cap head hex is made of steel,sturdy and durable[M3 Sizes]M3 x 4 - 25pcs, M3 x 5 - 25pcs, M3 x 6 - 25pcs, M3 x 8 - 25pcs, M3 x 10 - 25pcs, M3 x 12 - 25pcs, Hex nuts M3 - 50pcs,Flat washers M3 - 50pcs,Spring washer M3 - 50pcs.[Wide Application]Socket cap screws assortment Kit is an Perfect for home and workplace,woodworking,construction,plumbing,3D printed projects,ship assembly and so on.[Plastic Box]All of screw and nuts will be packed in a plastic clear box, easy to classify.Material:steelcolour:blackPackage Contents:300 x Head screw bolts setOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.