The Grover Sta-Tite Ukulele U98-18 series ebony button tuning machines provide precision tuning for your ukulele. You'll achieve accurate tuning thanks to the 18:1 gear ratio and open gears, allowing for fine adjustments. The die-cast plate and .994" posts are durable yet lightweight, designed for ukuleles. The multiple interchangeable ebony buttons allow you to customize the look. These tuning machines drop right into your ukulele for an easy upgrade and are a perfect replacement for the U98-18 series. For crisp, stable tuning on your ukulele, the Grover Sta-Tite Ukulele U98-18 series ebony button tuning machines are an ideal choice.