On Chance Hull 10 replace all four in 2015 . Bought 414 in size ,all opening are now install with screens great cross ventilation. I purchase them from Fisheries Supply . I also used the one with the closing knobs for a better seal . They were Beckson P.O. BS-2-1 with the knobs . The Cams were 414-BS-10 . Used pearson site for information on install very help full. On voids between the inside liner and outside truck cabin, put rod foam to keep West epoxy from running out . You must thicken the epoxy also to do sides and top, use spacer and clamps as pearson site shows.
Bob K
