Look for the words air in and air out on check valve. Install valve in the airline between pump and the top of aquarium (outside aquarium). Lee's Check Valve is intended for use on all aquariums where the air pump is on a level lower than the water surface.
Install only as directed.
Internet Price: $3.99 Today's Price: $3.19 (Save 20%)
Shop All Products By Lee's
Usually Leaves Warehouse the Next Business Day