This 8 Frame Inner Cover is made with the same rigid standards as our 10-Frame Inner Cover. The 3/8" plywood is glued and nailed into a rabbet in the pine rim. This is the strongest inner cover on the market today. A hole is cut in the inner cover to enable you to use a plastic bee escape. Also we cut a dado in the top rim for better ventilation and as an upper entrance/escape for the bees. Professionally Assembled.