Product Information: Includes 2 sets, each with 3 sealing rings. There are 2 O-rings on the water tank/female side and 1 O-ring on the motor/male side. One set can be used directly, and the other set is a backup, allowing you to ride worry-free. Wide Compatibility: Compatible with many 1999 and newer Harley-Davidson EFI motorcycles equipped with fuel line quick disconnect. Fits Sportster, Dyna, Touring, and Softail series models, including common EFI configurations. Good Sealing: Fuel line o-ring made from high-quality FKM rubber, offer good resistance to fuel, heat, and aging, helping ensuring reliable sealing performance and long-lasting durability in EFI fuel systems. Bulk for Pros and DIYers: Disconnect the fuel line quick connector, remove and clean old O-rings, install the new O-ring flat in place, reconnect securely. After-sales Service: If you have any questions about compatibility or installation, please contact us and we will assist you promptly.