Vance and Hines FP4 Fuelpak Tuner for Many 2021-2023 Harley-Davidson—Red 6-pin CAN Bus Data Port ConnectorVance and Hines FP4 Fuelpak Tuner for Many 2021 2023 Harley DavidsonRed 6 pin CAN Bus Data Port Connector Arguably the easiest to use and one of the most powerful tuners on the market today, Vance and Hines' Fuel Pak has taken the market by storm. And why shouldn't it? It works well and it's astonishingly fast and easy to use. FP4 upgrades include the latest Bluetooth technology, smaller size, upgraded app, and tuning capability for late model Harley