I have a 556 mini grip that requires me to remove the thumb stud when I use my edge-pro system to sharpen it. I happened to lose one half of the stud and inquired about buying a new one. The Benchmade rep sent me back an e-mail and said they would cover it under warranty and that the thumb stud was in the mail and would be at my house within a week. In case you didn't know, benchmade has great customer service!