The very excellent Electron EVS3505 EVS2606 and EVS2808 central ducted vacuum cleaner system pleated Poly main dust filter, this filter replaces the older foam style and is far, far better!
Should the filter become displaced, or loose it's filtering capacity, dust will clog the gauze before the motor, and unless the motor is removed by a competent person, and the gauze cleaned, performance will be reduced with no apparent reason.
It can be brushed off or preferably vacuumed off with another machine and then replaced in the unit.
At the moment, standard postage within Australia is capped at a maximum of $20!
We at TVD carry out in-home repairs on built-in ducted vacuum systems in the Perth area from $135, call 08 9362 6044