How does the Gutter Pump work? www.paneintheglass.com shows a video.

The Gutter Pump fits inside your gutter. Part of The Gutter Pump goes into your downspout. The design of The Gutter Pump allows water to flow through the device while blocking leaves and debris. The Gutter Pump has no mechanical parts. The best way to understand how it works is as follows. Fill you sink up with water and submerge your glass with water. Turn your glass upside down and slowly lift the bottom of the glass above the water line. Notice when you pull the bottom of the glass out of the water there is still water in the glass even though the glass is above the water line. The Gutter Pump works in reverse. Water on the bottom of your gutter is drained by The Gutter Pump through your downspout.