Check the listing for details. 12Pcs M6 Half Round Roll in Spring t Nuts 3030 Series t Slot Spring Nuts Silver. Condition: New, Made in China. Listed at 15.43 USD. These half-round spring T-track nuts integrate seamlessly with 30 series aluminum profiles, providing efficient assembly. Widely used in 3D printer bases, CNC routers, industrial aluminum frame structures, robotics projects, milling fixtures, and custom furniture frames, etc.SpecificationsColor: SilverMaterial: Carbon SteelThread Type: M3Compatibility: 30 Series Aluminum Extrusions (8mm Slot Width)Size: 20.5 x 11.5 mm / 0.81 x 0.45 inch (L*W)Height: 6.7 mm / 0.26 inch, 8 mm / 0.31 inchPacking List: 12 Pcs x T Nuts Roll in SpringAdvantagesT-nuts are made of carbon steel, with high hardness, corrosion resistance, oxidation resistance, nickel plating on the surface, and good rust resistance. The spring mechanism can be quickly installed and firmly fixed in the T-slot.