Evil Energy 6An Male To 3/8" 5/16" Quick-Disconnect Female Efi Fuel Rail Product Details [Size] The thread size of 6an is 9/16-18UNF. The ID of the screw is 3/8 inch and 5/16 inch. [Seal] The 6an flare efi fitting is sealed at 37 degree angle to avoid leakage. [Parameter] Working pressure: 1500psi; Temperature range: -40F-250F. [Material] Made of aluminum alloy 6061-T6. Spring lock is made of plastic. [Application] Widely used in engine fuel rail, ls swap, transmission cooler, return line, fuel sensor, etc. Payment We accept PayPal and credit cards via PayPal. Taxes - US We collect sales tax, as required by law. Shipping We make every effort of shipping within 3 business day of payment clearing. The estimated delivery time is 2 - 5 business days from the shipping date. Policies If you do need to return your item, please contact us via email (you will receive an email when your product ships with additional details - Subject: Important information about your purchase). You will then be provided with a return shipping label and packing slip. Pack the item carefully. Include the packing slip, apply the shipping label, and return the item within 30 business days of the date you request a return, or your return will be canceled. Once we receive your order we will inspect the return. Please allow up to 5 business days of receiving the returned item for your refund.