A device for stimulating a living being having proximal end having an electrical connection to an implantable medical device; having an oblong medial section having a first external diameter, which has at least one first dielectric outer envelope, at least one electrical conductor, at least one electrical stimulation and/or measurement means on the distal end; having distal section having a second outer diameter, which has at least one second dielectric outer envelope and at least one electrical conductor; having distal end having at least one electrical stimulation and/or measurement means; and having a lumen running in the longitudinal direction at least through the proximal end and the medial section. The first external diameter is isodiametric to the second external diameter, the first dielectric outer envelope has the same material properties as the second dielectric outer envelope, and the medial section has a lesser flexibility than the distal section.