Compatibility: This lawnmower blade disc is specifically designed to fit various models of the series, for 420 (2016 - 2017), for 430X (2016 - 2017),for 430X (new) (2018) ,for 440 (2017),for 450X (2016 - 2017, 2018),for 520 (2018),for 550 (2018),a perfect match for optimal performance.
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