Variable Speed Control For Koi Pond & Waterfall Pumps Controls water flow rate - crank it up for a dramatic display, down to a gentle flow to reduce energy costs Optimize filtration performance - increase flow during peak algae season Match your mood - crank it up for a pond side party or down for gentle flowing water Eliminates the need for energy wasting ball and gate valves 15 AMP Peak Capacity, works with pumps to 8,000gph