Sight Glass Spigot for Imperial and Crown Berkey No more guessing and running out of filtered water. This Berkey sight glass spigot allows you to instantly read the water level in the lower chamber of your Berkey water filter. Fits the Imperial Berkey and Crown Berkey (sold separately) . <>Replaces original standard spigot on your Imperial Berkey Water Filtration System with 2 Black Berkey Purification Element Filters, Gravity-Fed, Stainless Steel, 4.5 Gallon or Crown Berkey Water Filtration System with 2 Black Berkey Purification Element Filters, Gravity-Fed, Stainless Steel, 6 Gallon water filter . The glass tube of the spigot can be easily cleaned with soap and water as needed. Comes with two washers and a wingnut. Tube length: 13".