There are three ways of attaching the neck to the body of an electric guitar: set necks where the neck is glued to the body with a tenon joint (most Gibson guitars), through necks where the neck & body are made from the same piece of wood and bolt-on necks (most Fender guitars). It is almost a given amongst guitar players, that through necks sustain better than set-necks and bolt-on necks have the worst sustain.