Glass transparency give superb appearance to your aquarium. Make an elegant curve line in your aquarium.. Surface skimmer removes surface scum effectively. More easily and help photosynthesis of water plants.. 360-degree inflow design allows water flows get through from all directions without clogging and provides convenience in cleaning.. 13mm outer diameter fit the canister filter tubing of 1/2″ i.d. (12/16mm). Compatible with Eheim, Tetra and other filters.. Package included: 1x glass lily pipe surface skimmer inflow, 2x suction cups..