About this item [Size] Inner hole diameter: 0.51 inch (12.9mm). Fit for clamping and mounting 6AN fuel line. [Material] Aluminum alloy 6061-T6. [Function] It can use to secure and separate transmission lines to keep your project clean and organized. [Application] Fuel hose separator clamp wildly used in fuel hose, oil line, brake line, gas line, water pipe etc. [Note] Five sizes of hose mounting clamps available, please measure the OD of your hose before purchasing .