Product Type4040 Series T Nuts, M8 T Slot Nut Hammer Head Fastener Nut.Merterial All of them are made of high hardness nickel plated carbon steel, with good rust resistance and better performance, durable for long time use.Package includePack of 100.Application suitable for 2020 series aluminum profile, widely use for building industrial aluminum frame structures, 3D printers, CNC Routers, CNC laser cutters, robotics projects.Easy To InstallThey can be directly into the aluminum slot hole in any of the assembly post, back spring can be fixed its position which make installation very simple and reliable.They are simple to use and convenient to connect aluminum profiles to other parts,easy to install