A non-toxic, non-corrosive lubricant that works on all nut, saddle, and bridge materials, not known to harm finishes. The 0.5cc applicator syringe is good for up to 50 string changes; fits easily into an accessory pocket. When applied to string bearing surfaces, it stabilizes tuning, improves playability, reduces string breakage, and stops wear-and-tear at the points of friction. It's good and thick and stays where it's put.