Now, you can level your frets...with the strings ON!This revolutionary new tool lets you level your frets under full tension without removing the strings. It's designed to work with our 1" wide abrasives for ultra-fast set up and leveling.Fret work without guessworkWith the Fretbar you'll level the frets with the exact tension the neck has when played, because the Fretbar fits UNDER and BETWEEN the strings, with the guitar tuned to pitch. The precision-ground surface is just 5/64" thick, allowing you to glide under the strings when leveling.With the neck under tension, you'll clearly see every hump, twist, high or low spot, so you can level the frets without worry or any "surprises" that pop up after the job. No more wasted strings or sandpaper!Our 9" length is designed for smaller necks like ukuleles and mandolins. It also works for leveling full scale necks and spot leveling.We also include the String Jack to use with the Fretbar. Put the jack in front of the nut to raise the strings without changing the tension on the neck.Built for a lifetime of useDurable extruded 6061 aluminumGuaranteed accuracy of ±0.0015" per footWorks with our custom 1" wide AbrasivesWorks with the strings on or offOur Abrasives cut like a file, last longer than regular sandpaper, and are sized to stick right to the 1" width of each Fretbar.Each set includes one Fretbar and four 15-yard rolls of Abrasive, one of each grit: 320, 400, 600 and 800-grits.The Fretbar is 3/4" (19mm) wide x 1-15/32" (37mm) tall extruded aluminum, and 9" (228mm) long.Works on stainless frets, too!Our own shop experience indicates stainless-steel wire does not cause premature wear of our files or sandpapers.