Underwater Galleries Cichlid Stone "Big Rock Box" 10 Stone Kit was created for those who want more large rocks for thier fish tanks, to either
build their rock scape taller faster, or because they have
!larger fish in their aquarium!
Either way this Kit fits the bill; it has no small stones only medium  and large, all pictured on the label!
They have only one opening each; opening sizes ranging from 1 3/4 " to 2 3/4 " for larger fish. 
Wonderful for creating a complex environment of crevices and caves, they are a vast improvement over ordinary stone!
 
*Cichlid Stones are light and won't endanger the glass
*won't leach unwanted minerals into the water like some ordinary stone 
*create hollow cave spaces for the fish to claim as territory space
* made from Earth- Friendly Ceramic 
* hollow - will not displace tank water which will give the tank more carrying capacity
* single openings in each stone so that it will function as a defensible space for individual fish in a community tank providing more harmony and less aggression in the aquarium