This is a corner mounted bee escape. Drill a 50mm hole in each corner of an escape board and mount the escape under each hole. It is too late in the season for me to test them this year so any feedback from bee keepers with longer seasons would be appreciated.

I think the openings are to narrow to allow drones to escape so they should be used after the drones are expelled. I use 4.9mm comb so the openings may be tight for 5.3mm bees but I think it should work.