26" Waterfall Opening Measures 35" x 36" x 28". Provides biological filtration to ponds up to 600 square feet and/or approximately 6000 gallons. Maximum recommended flow 120 gpm. Includes two 2" bulkhead fittings allowing you to enter incoming water from either side of filter. Filter comes standard with three filter mats and three mesh bags for filter media. Ships via motor freight.