The ATE Master brake cylinder (03.2120-3943.3) is a professional-grade replacement component engineered for long service life and reliable operation across all conditions your vehicle encounters. The part is built to the following specification: Diameter [mm]: 20, Plastic mm, Thread Size: M10x1, Material: Aluminium, Number of connectors: Copper, Brake System: ATE. Each dimension is checked against the OEM reference to ensure the component seats and functions correctly first time. Verified to fit SEAT, VW models. All compatibility data is cross-checked against the TecDoc database — select your vehicle to confirm the part matches your specific engine and year. This part supersedes original equipment references: 0 204 123 286, 0 204 123 375, 0 204 123 466, 0 204 123 562 and 45 more. Matching these numbers confirms a like-for-like replacement with no loss of function. ATE is a recognised supplier of automotive braking components to independent workshops and dealer networks across Europe. All parts are sourced from authorised distribution channels and carry full manufacturer traceability — you receive exactly the same component supplied to professional garages and dealer workshops. If fitment or specifications do not match your vehicle, our technical team can help identify the correct alternative — use the vehicle selector or contact us with your VIN for a guaranteed-fit recommendation. Replacing worn components on schedule preserves your vehicle's safety, reliability, and resale value — and aftermarket parts from established brands deliver OEM-equivalent performance at a fraction of the dealer price. Every part is dispatched from our UK warehouse with a 30-day money-back guarantee and free hassle-free returns.

ATE (Alfred Teves), founded in 1906 in Frankfurt, Germany, is one of the most respected names in braking technology, now part of the Continental Corporation. ATE specialises in brake pads, brake discs, brake calipers, brake fluid, and hydraulic components. As the original equipment supplier to Volkswagen, Audi, BMW, Mercedes-Benz, and Porsche, ATE sets the standard for braking safety. With over a century of braking innovation, ATE parts provide the confidence of OE-quality stopping power in every driving situation.