This T-Nut KIT includes (10) T-Nuts engineered for maximum performance and compatibility with the Chief Products roof rack system. Chief now offer them in (3) sizes (M6, M8 & M10) to accommodate any accessory you find. Designed to fit perfectly within our Planks and Tie-Down Plates. These high-tensile 10.9 Grade T-Nuts can handle anything you throw at them. Blackened to look great when installed, and coated in Black Oxide to ensure they stay that way even in the most hostile environments.