Here's what Dunlop say about their capo:

"The Trigger Fly Capo builds on our most popular capo design with better handling and tuning stability than ever. The grip is streamlined for a more comfortable, ergonomic feel, and a specially engineered custom spring mechanism applies balanced pressure for easy placement and precise intonation up and down the neck—even as high as the 7th fret of most acoustics. Thanks to an optimized fret pad, chords and single notes alike will ring out with smooth clarity."