Fluval Multi-surface substrate cleaner, gravel vac. Effectively traps dirt and debris Easy Start siphon for quick priming – starts with just a couple of pumps Thumb-operated flow regulator allows you adjust speed as you clean Gravel guard prevents clogging Tube extension included for larger tanks and hard to reach areas Suitable for all substrates (sand, gravel, rock) For use in freshwater and saltwater aquariums For aquariums with a depth of 20 – 50 cm