The Hipshot Grip-Lock is proven to hold strings tightly, allowing the guitar to stay in tune to improve playing enjoyment. The Grip-Lock is a mechanical type locking system that can be used on any guitar, including non-trem or acoustic. Upgrade your tuners and improve the tuning accuracy and stability of your 3 + 3 headstock guitar with Hipshot's Tuner Upgrade Kit. With the patent pending UMP™(Universal Mount Plate) included free in this kit, tuners will install on most guitars without drilling in your headstock. (Note: We have seperate kits for the PRS Guitars)