Double Screen Board has several purposes.  Can be used in winter time to allow warmth from a large colony to flow upwards through screen board and provide warmth to a smaller colony located above.  Available for 10 FRAME and 5 FRAME.
For queen rearing the 10 FRAME unit has additional doors on 3 of the sides and functions like a Snelgrove board.  It can be placed between an old and new hive and the old bees will make their way back to the old hive, leaving young bees with the new queen. Ships assembled. Compatible with 10 Frame equipment only.
