ART® stands for Adaptive Radius TechnologyTM, which is a patented mechanism created by G7th that sits underneath the string pad on both the Performance 3 and Heritage capos. When the capo is attached to the guitar, the ART® automatically responds to the radius of your guitar neck and the gauge of your strings to perfectly distribute pressure over the strings, giving you MAXIMUM tuning stability with the MINIMUM tension required.
The biggest complaint from guitarists about capos is the lack of tuning stability - put on the capo and it pulls your strings sharp. While the severity of the problem depends on many factors, including the pressure put down by the capo, string gauges, action height and fingerboard radius, the problem is not completely solved by being able to adjust the pressure on your capo. The fundamental problem still remains - the pressure is not being evenly distributed which causes some strings to be pulled out of tune, frustrating beginners to professional guitarists in their playing.
The Adaptive Radius Technology string pad distributes pressure over the strings perfectly by responding to the fingerboard radius of the guitar on which it is placed.