Simply wind up the Clockwork Fish clockwork mechanism, then release it to set the fish's in motion. Place the fish in water and it will swim and splash across the surface. Wind up fish toy that uses a clockwork mechanism to swim through water. Simply twist the plastic key on its side, then release to make the fish's tail swish back and forth. Drop it in water, and it will swim. Fish toy that swims Clockwork mechanism powers tail Wind up to activate.