Planet Waves NS Capo Pro
This slim, very lightweight aluminum capo fits most radiused fingerboards. Mark uses it successfully on all of his main guitars: a '66 Martin D-28, a Collings SJ, and a Goodall CJ. It can be operated easily with one hand, works well on both 6- and 12-string guitars, and costs only $14.95! Black anodized finish. The design is by Ned Steinberger.