Remove the cracked cover, place a plastic dishpan over the vent with a brick on it or as suggested install the MAXXAIR vent covers to shield the vents for feature protection. Take the cover with you to your local RV dealer / camping world, they have replacements. While you are at it check your round vent covers (white) that are over the kitchen, bath, vents they may need replacing also... The crank up square vent covers are prone to OZONE damage and are not UV protected. Make sure you get white MAXXAIR covers. The black or brown covers look cool but trap a lot of heat because of the dark color.
Good luck on your adventure of replacing the covers
Sid & HRH MISSY, SHIH TZU
2019 WILDCAT 28 SGX
2014 F-250 KING RANCH PS 6.7L/SWD/6R140/BFT
TST Truck System Technologies TM-507SE
DAYS CAMPED 2021 16 DAYS