Camco Aero-Flo Vent Covers Model 40421 March 16, 2010, 05:08:32 pm Yahoo Message Number: 111081I removed mine today to Eternabond the surrounding seams. In doing so, I did not see any deterioration or brittleness that other have reported. These were installed Sept 07 and rig has been outdoors without a cover the entire time. Maybe things have improved in their manufacturing. Joe Hamm-San Jose