Professional grade, high-density polyethylene, double walled structure gives it superior strength and weight distribution 18" diameter recessed middle area allows for larger pieces to be backfilled in order to increase stability Extra large water storage area holds up to 75 gallons of water which means less topping off and can accommodate pumps all the way up to 4,000 GPH Two 9" x 12" pump access panels to allow multiple pumps and easy access for maintenance Pre-drilled hole in the centre for easy plumbing hookup Measuring 45" x 45" x 14", the AquaBasin™ is ideal for catching the splash of some of those larger fountains Octagonal shape for maximum strength when backfilling and positioning decorative pieces