There must be a misunderstanding. If a bass is Neck-Thru or Bolt-On that does not prevent using any particular strings. However, if the strings are threaded through the back of the bass and around to the top can prevent certain strings such as La Bella Flatwounds from being installed. These strings will work on any basses where the strings are "Top Loaded." However if the strings are strung thru-body they may not work on the instrument. It is best to reach out to us with any specific fitment questions directly via our "Contact Us" page and we will assure fitment is suitable for your instrument.