The Festool 500558 CT-SYS Replacement Filter is a replacement main filter for select Festool dust extractors. This is a main filter designed for capturing fine dust in Festool CT SYS and CTC SYS extractors. Model Number 500558. If you are running a compact Festool extractor for shop work, install work, or punch-list cleanup, this filter matters because it helps keep fine airborne dust under control while protecting extractor performance.

This filter uses standard 1-micron filtration and is built to trap residual dust that is not retained by the filter bag. In real use, that means cleaner exhaust air returning to the room and better control of the fine dust that tends to hang in the air the longest. Festool also states that it maintains airflow while filtering down to 1 micron, which is the balance you want in a dust extractor filter: solid filtration without choking the machine early.

For users working with wood dust and other fine jobsite debris, that airflow piece is a big deal. A filter that cakes over too fast cuts suction and fills up your day with unnecessary maintenance. The Festool 500558 CT-SYS Replacement Filter is designed to let the extractor reach full capacity without clogging or caking as quickly, so you spend more time actually working and less time fighting reduced performance.

As a main filter accessory, this part is there to support the extractor system, not replace the bag. It filters residual dust after the filter bag has done its part, which helps keep the extractor's internal components cleaner and supports cleaner air discharge. It also provides motor protection, which is exactly what you want from a properly fitted replacement filter in a compact dust extractor.

Festool lists this replacement filter for dust classes L and M and specifically for CT SYS and CTC SYS units. It is not suitable for mobile dust extractors with AUTOCLEAN function, so fitment matters here. If you are ordering by part number, 500558 is the one to match against your compatible CT SYS or CTC SYS extractor before checkout.

Build-wise, this is a simple part, but simple parts are where correct fit and reliable filtration matter most. The fiberglass construction listed in supplementary data, washable design, and compact rectangular format all point to a service part made for quick replacement without turning routine maintenance into a project. For pros who rely on compact extraction in finished spaces, service vans, or small shops, replacing a tired filter with the correct one is one of the easiest ways to keep the machine doing its job properly.

Who should buy it? Anyone already running a Festool CT SYS or CTC SYS dust extractor and needing the proper replacement main filter. It makes the most sense for woodworkers, remodelers, installers, and finish trades that work around fine dust and need compact dust extraction that stays efficient. If you need a filter for an AUTOCLEAN extractor, this is not the one. If you need the correct 1-micron main filter for a CT SYS platform machine, it is.

Festool 500558 CT-SYS Replacement Filter Keeps Your Compact Extractor Doing Its Job

If you own a CT SYS or CTC SYS, this is one of those maintenance parts that is boring right up until your extractor stops pulling like it should.

• Who it's for: Festool users running CT SYS or CTC SYS dust extractors for woodworking, remodeling, and clean interior work.
• Why it stands out: The 1-micron filtration and airflow-focused design make it a proper replacement part, not just a close-enough filter.
• Worth knowing: This is not for AUTOCLEAN machines, so check your extractor model before ordering.

• What extractor models is this filter made for? It is listed for Festool CT SYS and CTC SYS dust extractors.
• What level of filtration does it provide? This is a 1-micron replacement main filter designed to trap particles down to 1 micron.
• Can it be used with Festool AUTOCLEAN extractors? No. Festool states it is not suitable for mobile dust extractors with AUTOCLEAN function.
• Is the filter washable? This filter is washable.