JBL Proclean Aqua Ex 45-70Substrate cleaner (gravel cleaner) for cleaning aquariums with 45 70 cm in height Sophisticated and highly effective gravel cleaner to siphon off waste in aquariums from 45 cm height upwards Use: shake the gravel cleaner, let water flow into the bucket, siphon the waste out of the substrate, close the stopcock when finished The round gravel cleaner has one corner which helps you move the dirt and reach the corners of the aquarium when you turn it Safe