The five differently shaped Boon Pipes can be used individually or put together to make a chain for a flow of watery fun. Add in Boon TUBES, and there are now eight watery wonders to discover. Each TUBE and PIPE interacts with water differently for plenty of ways to experiment. Boon COGS completes this set for maximum bath time fun. They spin when water is poured over them. Positioned just right, they'll run like a fine-tuned machine. These bath toys suction to the wall so the water goes back in the tub, not on the floor.