I use homemade Vent boxes,they are made from 1 X 4's , the center hole was enlarged,then a piece of # 8 wire was stapled over the hole.
Using a Illinois box, I can feed from a Qt. jar setting on the wire, I can refill jar with out any flying bees.
For winter I cover the #8 wire with a small piece of cardboard then fill the box with wood mulch, this insulates, breaths, and also absorbs any moisture from the hive below.
During the winter, on a sunny day I can brush the mulch aside, remove the cardboard and look into the hive below, most of the time seeing bees moving around. [ curiosity killed the cat they say, but still fun to look ]
I really like them
Bee-Bop