Penn-Plax presents the Cascade 200 Power Hang-On Filter. This filter quietly delivers crystal clear water and pushes water at 185 Gallons per Hour (GPH) for tanks up to 55 Gallons in size. It’s great for Freshwater and Saltwater Aquariums. Shop Penn-Plax for All Your Pet’s Needs: Penn-Plax is a manufacturer and distributor of top quality pet supplies who specialize in creating excellent pet products for animals both great and small.