The Aquarium Liquid Timer contains a tank full of coloured little fishies that bubble and move around before slowly sinking to the bottom of the tube. Simply shake or turn over to reactivate the fishes to recommence their swimming. Height: 15cm. Consumers may buy individually. Warning: These products are made from acrylic plastic. They will not withstand being thrown or dropped onto hard surfaces. They contain mineral oils which may smell strongly if the product breaks. The contents are not toxic and are approved to Australian safety standards, however please under supervision to ensure safe use of the product.