Flip Manufacturing part number: 705419. Please verify your model is listed below for the correct fitment. See Fitment Below: X300 with all 48c decks X300 with 42in Mulching with serial number that begins after 150001- X304 42in Mulching deck serial number that begins after 150001- X320 48in rotatable decks beginning with serial number 085001- all X320 with 54in deck X324 48in rotatable beginning with serial number 085001- X340 with 54in beginning serial number 085001- all X360 with 48in decks X500 with 48in rotatable beginning with serial number 030001- 54in beginning with 030001- X520 with 48in rotatable beginning serial number 030001- 54in beginning serial number 030001- X530 all 54in decks X534 with 48in rotatable beginning with serial number 030001- 54in beginning with serial number 030001- X540 with 48in rotatable beginning serial number 030001- and 54in beginning serial number 030001.