We occassionally have some units that were either used as test units or have small imperfections due to manufacturing issues or minor damage in shipping that prevent us from selling them as first quality units. 

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Any imperfections on these units will not be noticeable when installed in your aquarium or easily camoflaged, but they may arrive with some sand or gravel in the unit from prior use.   

 

When Available these units are offered for sale on ebay as "used" units at the following link