The TonePros System II Bridge and Tailpiece components come as a package set, ready to install on your guitar. The package includes: 1. TonePros Patent Issued System II Pre-Notched Bridge with matching threaded adjustment posts. 2. TonePros Patent Issued System II Tailpiece with matching threaded adjustment studs. 3. Allen style adjustment tool for use with both bridge and tailpiece. The LPM02 includes the TonePros T3BT Bridge and T1Z Tailpiece. These matched bridge and tailpiece are metric thread and fit most overseas guitars without modification.