The Trident 3 pumps by ReeFlo feature a unique 3-speed AdjustaFlow switch that allows you to instantly choose flow rates, pressure and watt draw from three different settings. Cut the flow and watt draw in half during the night or at feeding time and then instantly switch back when desired. Very low heat transfer The Trident 3 pumps feature a FlowThru design that prevents the water from picking up motor heat while churning inside the pump head. The Trident 3 uses an aluminum cast motor which dissipates heat before it can reach the water. Nearly Silent Operation The Trident 3 pumps employ graphite motor bearings to ensure the quietest operation. You will have to put your ear near it to hear it.