The new Self-Start Siphon feature has made aquarium maintenance a whole lot easier! With the Gravel Vacuum cylinder submerged in the water simply move it up and down a few times to activate the Self-Start Siphon. Gravel Vacuum Cleaners are designed to separate and remove debris from the aquarium during routine water changes. The Stretch Gravel Vacuum Cleaner is ideal for use in designer aquariums and those hard-to-reach areas in most all aquariums. It features a 1” diameter cylinder and a 15/16” diameter cylinder with a telescoping ring that allows the Stretch Gravel Vacuum Cleaner to extend from 9” to 17” in length and it comes standard with a 56” long hose.