Controls - 28 HT220 Operator’s Manual Center Console CMW Item Description Notes 6. Left track filter indicator Light comes on when the left track filter needs replacing. 7. Double filter indicator Light comes on when the double filter needs replacing. 8. Right track filter indicator Light comes on when the right track filter needs replacing. 9. Single filter indicator Light comes on when the single filter needs replacing. 10. Digging filter indicator Light comes on when the digging filter needs replacing.