The Fender Mojo Grip is a nitrile rubber sleeve that provides a better gripping surface, and extra thickness to a 351 shape pick. The grips come with a Celluloid pick already in place. The best part of the Fender MojoGrip is that the grip is separate from the pick. If you wear down or break your pick, just carefully slide the pick out of the grip and replace it with another pick.