The Waterview Spigot is a simple yet ingenious way to know at a glance just how much water your stainless steel Berkey system has in the bottom chamber. This glass tube acts as a water gauge displaying the water level inside the lower reservoir and takes the guess work out of when and how much water can be added to the upper chamber. The spigot installs the same way as the original one that ships with the Berkey and is operated the same way. But it's the Waterview Spigot's vertical glass tube that fills to show precisely the level of water inside that makes all the difference. By replacing the original spigot with the Waterview Spigot, you can end the guess work or messy checking of water levels and always know for sure how much purified water is available.