Tach Syncro With Red Needle, part number AR50406, is compatible with John Deere tractor models 3010, 4000, 4010, 4020, 4320, 4520, 4620, 5010, 5020, and 6030. This component replaces OEM part numbers AR26718, AR32833, AR45444, AR48021, AR39906, AR39908, AR30143, and RE206855. Always verify part number and equipment model before ordering to ensure proper fit.