After trying TI jazz flats and really liking them on my p bass and jazz bass, I decided to try to set of jazz rounds on my Zeidler headless bass. The Zeidler holds the strings in place with a setscrew. Unfortunately the TI rounds don't hold up under the pressure of the setscrew. Not sure how many other basses use that system, but thought I would put it out there to hopefully save someone else $67.