There are three different types of Blocking Plugs:

  1. Black Blocking Plugs come standard in all Berkey Light® systems and some stainless steel systems. The black plugs are made of FDA approved Buna rubber.
  2. Off-White Blocking Plugs may come with the Berkey Light® and some stainless steel systems. The off-white plugs are made of food grade M18 pure gum rubber.
  3. White Screw-Type Blocking Plugs are used in some stainless steel systems. These come with a nut, a screw and two clear washers. The nut and screw are made of Polypropylene. The washers are made of food- grade silicone.

Please keep in mind that the water in the bottom chamber of your unit will not touch any of the Blocking Plugs. The water will be filtered before it reaches the bottom chamber.