Have not replaced yet as system is not quite ready for change. Just wanted to be ahead of the game. Have had a Nova system in two homes and it is the best for the money.
This is set of three cartridges, 2 Sediment and one Nova Super CocoNut Carbon, (Our proprietary carbon has the highest purity rating in the USA).
If you need a wrench add to order here
shipping charge or shipping is $12