I like Gruvgear products. I saw the Fump in their social media feed and thought it was a neat idea, so I ordered one. Colour me unimpressed - it's distinctly unsubtle and it messes with your intonation. It's well made and rugged, but it needs to have softer material or something. It doesn't replicate palm muting unless you have lousy palm muting technique! Nice idea, but poor execution.