*Made of the polyurethane foam, durable, non-toxic, no element leak out, no influence on the pH level of the water.
 

*All the paints of the boards are made of the environment friendly materials. No dissolve in the water, safe for the fish. No danger for the fish chew and swallow a little.
 

*Perfect third dimension and imitating the nature living environment for the fish, providing best looking effect.
 

*More concave places for the fish to hide out, reduce the conflict between fish.
 

*Both same items can combine by the same waving borders, to build up the continuum background.
 

*Easily cut by the knife and stick on the glass of tank by silicon glue. Have the features as easy set up and take off, etc.