These are low profile replacement M8 Stainless Steel T-nuts for the any hydrofoil that uses the M8 T-nut, which just about all Tracked hydrofoils.These are low profile meaning they are thinner than stock brass T-nuts by about 2.2mm from top to bottom but STRONGER. See the video below for some of the testing including breaking T-nuts in slow motion. These are also available in M6 on a separate product listing. set of 10 qty