I purchased this thread adapter (Windtrax.com 22595) for my Erie Wheel Wizard brush. It is a 1/2" mpt to 3/4" acme. I purchased this piece to fit on my foam brush handles (which are 3/8 fip x 1/2 mip). Which means it does not fit correctly. I should have checked before I ordered one, but it did only cost $3.78.
The dogs liked it though.