Redhorse Performance 8163 Series AN to Metric O-ring adapters are the perfect solution to your plumbing needs. The O-ring fittings provide a leak-free seal, and the durable anodized finish stands up to harsh automotive conditions. RHP offers these lightweight aluminum adapters in multiple sizes to help you complete your custom job with precision and style. Order the AN to Metric O-ring adapters that will provide the best fit for your project needs.