Boeray 50pcs M4 Carbon Steel Drop in Hammer Head T Nuts for 2020 Series Aluminum Extrusion with Slot 6mm Material: High Quality Carbon Steel Thread Type: M4 Length: 10mm/0.39" Width: 6mm/0.24" Thickness: 4mm/0.16" Total Size: 10x6x4mm/0.39x0.24x0.16"(LxWxT) Used for: Insert into the aluminum profile 2020 series with slot 6mm and work together with screws to have fasten function Quantity:50pcs