Designed to boost bass guitar performance, TUSQ XL Fender Precision 4-String Bass slotted nut is precision engineered and specially formulated to bring out the hidden harmonics and richness in every note. TUSQ XL is based on the highly resonant TUSQ man made ivory, but impregnated with Teflon to improve the tuning performance of your bass. TUSQ XL will bring out hidden harmonics in your bass. The highly resonant material couples your strings" vibration to the neck better than anything else. You will hear more richness from every note, especially on open strings.