Convenient to use for rice and cleaning. Nichidou Wooper Meal Dropper Features: A convenient dropper that can be used to feed wooper and clean up the aquarium. The Wooperur responds to the bait that moves in front of your eyes, so when you suck the bait with an eyedropper, you can move it slowly in front of your eyes, it will stick to the pack. Quantity: 1 Size: Approx. 9.1 inches (23 cm).