ProLine Waterfall Boxes are ideal for creating the perfect waterfall in your pond or water garden. Featuring a sleek design that enhances the tranquil sound and beauty of free-flowing water day or night. ProLine Waterfall Boxes are designed to accommodate additional Mechanical or Biological Filter Media for super clean water. The extra-wide spillway accommodates greater water aeration. Holds More Friendly Bacteria to Help Filtration. Baffle Chamber for Even and Efficient Waterfall Flow Through Filter Media. Media not included in style 02481. Easily Buried In Ground To Hide Box from Sight. Extra Long Weir Lip for Stacking Stones in Front of Waterfall. Waterfall box has a Pre-Bored Inlet size of 3” to accommodate included fittings. Includes 2” Bulkhead Fitting and 1 1/ 2” Barbed Fitting. Unit Dimensions 16" L x 18.37" W x 12.25" H, Waterfall Width 16" Opening, Container Capacity 4 Gallon, Maximum Pump Flow 3000 GPH (pump sold separately).