The Hosco Visor Compensated Slotted Bone Nut for Stratocaster Style Guitars improves the intonation of the lower frets using their patented shape. Fretting the lower frets can cause intonation problems as the string stretches from the nut down to the finger pressing it behind the fret, the Visor nut overhangs the fretboard is certain places, reducing the length of the string, and compensates for this problem (similar to intonating bridge saddles to compensate at the high frets but at the other end of the string).
