These bottom boards are reversible: the deep opening (3/4") allows for an adjustable entrance that can be controlled with an entrance reducer, while the shallow opening (1/2") simply allows for year-round narrower entrances which reduces the need for an entrance reducer.
 
Comes fully assembled
 
Compatibility Warning:
	
Choose 8 Frame options for 8 Frame equipment
	
Choose 10 Frame options for 10 Frame equipment