The use of the right tool to perform the basic adjustments of your instrument is essential. The Premium Truss Rod Wrench from Music Nomad is loaded with features and benefits. Its construction from carbon steel offers quality, while the ergonomic design of the handle provides comfort and ease during use. The protective rubber "bumper" prevents the metal handle from getting stuck on the side of the truss rod cover. It also includes a magnetic screwdriver for the small screws found on the truss rod cover. With a size of 5/16", it fits perfectly with Gibson Guitars, PRS(USA) Guitars, Gretsch Guitars, and many more.