Floating Vibrato

This is a vibrato tailpiece, usually a Fender or similar fulcrum type (such as a Floyd Rose or Wilkinson) that doesn’t rest tight against the body of the guitar. In other words, the balance of tension between the strings and the springs in the vibrato is set such that the bridge is not pulled down tight to the body. The main benefit of this is that you can both raise and lower the pitch of the strings. The disadvantage is, if you break a string, the guitar goes out of tune.