How it's made. Printed in PETG - the plastic aquarium hides are sold in - with no paint or glue, so there is nothing to leach. Walls are 2.4 mm; the cave and the log are open at both ends with windows in the roof, so no air is trapped and a fish can always get out the way it came in. The sign's spike is 40 mm, for gravel or sand. The name stands 0.8 mm proud on its plate in its own colour; rinse before use.