Purchase a replacement filter for Apec come with 4 filter. First 3 10" filter is fine and the instruction is detail with all necessary cleaning process. The 4th carbon filter connector is not fit the original. Inquired seller and send 3 plastic adapter for connection. Unfortunately, that is not correct and I had to visit Home Depot for a set of 2 plastic connector to complete the job. Delivery period is rather long(over a week) and overall 2 delivery take half month.