This is a replacement Upper Chamber for the Berkey Light. It has 4 holes as opposed to the older Berkey Light model that only has 2 holes. If you are upgrading from the 2 hole upper chamber to this 4 hole upper chamber, please be aware that you will need 2 blocking plugs if you don't intend to use 4 black berkey filters. These 2 blocking plugs do not come with this upper chamber and can be found here.