Pre-motor electrostatic micro filter which protects the motor and gives S-Class filtraton. Suitable for all X7 machines, X8, X1, X2, X3, X1.1, X4, X4 EXTRA, X4 PET, X4 EXCEL, X5 EXTRA, XP2, XP3, X1.1 more→ECO, X4 EXTRA ECO, X4 PET ECO, X5 EXTRA ECO, EVOLUTION 300, EVOLUTION 350, EVOLUTION 450. Regularly changing the filters prolongs the life of the machine and ensures optimum performance.}