Craft Brew E-Series 4000 GPD is our line of economical Reverse Osmosis Systems and Carbon Systems. Each system is comes complete with lots of options. Just to name a few, UV, Blending Valve, Wired and plumbed for Anti-Scalant, Free Shipping in the Continental United States and Built in the USA. The E-Series can be ordered with Float Switch or Pressure Switch Controlled. All Pressure switch controlled come with a 44 Gallon RO pressure tank.