I have been using the wooden reducers that are roughly 5/8 inch square and have 3-4 different sized openings. These work fine but does anyone know of a type of reducer that stays on the hive and can double to close a hive for moving. I think I read somewhere about one that was a sliding unit that stayed on the hive. In one direction it reduced ot restricted and in the other was open. Maybe I'm just dreaming. Thanks in advance!!