The Scepter Ace replacement cell is designed to work outside of the filter. Why? because it works better and does not violate Watkins patent. Use the provided plug to fill the hole on the filter cap. Pictures here:






The Scepter Ace replacement cell is designed to work outside of the filter. Why? because it works better and does not violate Watkins patent. Use the provided plug to fill the hole on the filter cap. Pictures here: