Infinite Product Solutions and Tactical Innovations are good thread adapter brands. As of 2016, each of these brands has thread adaptors with customer ratings of 4.5 stars out of five or higher on Amazon.com.
Infinite Product Solutions' 5/8-24 to 13/16-16 filter thread adapter has a rating of five stars on Amazon.com. A total of 91 percent of reviewers rated this company and product five stars, and 7 percent rated them four stars.
Tactical Innovations sells a P22 thread adapter that is rated 4.5 stars, with 73 percent of reviewers giving the product five stars and 14 percent giving it two stars.