The PQ-M100-00 is a TUSQ nut blank specially designed to be used on Martin style guitars. It has an angled bottom and needs to be slotted. TUSQ delivers a rich tone, crystal clear bell like high end with big open lows and a significant increase in harmonic content and harmonic sustain. Increase harmonics equals more richness and character in your tone. Its the difference between a four piece choir and a twelve piece choir singing every time your play a note. Consistent quality Increased harmonic content Ivory white in color Precision slotted Measure Length Width Height E to E inches 1.89" 0.226" 0.420" NA inches 1 7/8" 7/32" 13/32" NA millimeters 48.01mm 5.75mm 10.67mm NA Note: All Graph Tech nuts and saddles are slightly long and wide to ensure extra room to achieve a perfect fit for your guitar. This extra material can easily be removed with fine grit sandpaper.Click here for the installation instructions and click here for 'how to measure your nut'