System 65 Guitar Tech Care Kit. Dunlop's Formula 65 has become the standard daily-use guitar care product line for pro guitar techs, repair shops, and guitarists worldwide. The System 65 Guitar Tech kit contains all you need to properly maintain your guitar's fingerboard, finish, and strings. Formula 65 Polish creates a genuine, no-residue shine in a hurry, with the proper chemical balance to preserve any finish. Fretboard 65 Ultimate Lemon Oil is the perfect complement as it cleans away fingerboard grime and returns your fretboard to its original luster. Ultraglide 65 String Conditioner shields strings from tarnish and corrosion, extending their playing life. This kit comes complete with two polish cloths and one genuine Dunlop Stringwinder.