Penn-Plax Premium under Gravel Filter System - for 40-55 Gallon Fish Tanks &...
Check out Top Highlights of the Under Gravel Filters by Penn-Plax. Clear Free filter plates lock securely together and prevent gravel from falling beneath the filter plates. Available for 5, 10, 15/20H, 20L/29, 40 / 55 gallon aquariums.