The MARINA Multi-Vac is a powerful 3 in 1 aquarium gravel cleaner, algae remover and water siphon. Since the Multi-Vac is battery operated, it eliminates the posibility of electric shock. A simple push of a button and the Multi-Vac jumps into action. The side bag makes it easy to trap debris or simply attach a hose when a water change is needed. The Multi-Vac is extendable from 8″ to 16″ which makes it ideal for most aquariums.