Incorrect description as the 1" thread on the filter housing is machine thread, not NPT. So you can attach to 3/4" connect Male NPT adapter ends only. But that's ok as you have the connector on both sides and you can easily remove/swap the whole thing if needed. There are also 3/4" female NPT threads in the threaded ends of the machine, but if you were using those you would have no connectors. I have installed them before, although they are more expensive branded products.
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