Their colour and structure improve the looks of your decoration inside the tank select the structured background str 450 or str 600 to fit your aquarium exactly they are easy to cut to the size you need and can be fastened to the inside of the aquarium with special aquarium silicone the decorative juwel aquarium background with their deep set bark structure strengthen the depth effect of your aquarium bring out your fish and plants special aquarium silicone deep set bark structure abut t