This rubber-based string best imitates the warm, vibrant sound of an upright bass. Similar strings are used on other 'Bass Ukuleles', like the Kala U-Bass. They are also extremely easy to fret, and last a very long time. However, they do require: a break-in period, more turns of the post when adjusting tuning and sometimes requires lifting the string above the nut to prevent thinning. Some bass players have also mentioned "stickiness" but this can easily be eliminated by using string lubricant or baby powder.