Campbell has been playing with ReString Zero since the start of the 2022 US Summer Swing. Most notably, last summer Campbell warmed up with US Open Runner-Up Casper Ruud (ATP Rank #2 at the time) before his semi-final and final with Zero in his racket. Here's what he has to say about the string:
"Did an entire grind session with Ruud. I was hitting pretty big but managed to get good control too. The string doesn't move in my racket, it's super slick! Usually I have to constantly move the strings back but not with this one! Really like it in my racket."