Secure your harnesses safely in your car with this eye bolt from Grayston. The tread measures 23mm long, which is the perfect size to use in the floor with a spreader plate, and the 7/16 UNF thread matches the factory seat belt mounting points. The 8.8-grade high tensile steel is extremely strong and finished in rust-resistance zinc plating. Generally, four are required per harness as the shoulder straps are usually looped over a harness bar.