Flexible tube of an endoscope

Flexible tube of an endoscope, comprising an outer tubular member (12) on the outside of which a synthetic resin layer (13) is formed, on its outer side a coating (14) to protect the resin layer (13) is applied prior to disinfectants, wherein the cylindrical outer side of the resin layer (13) has at least one recess (15), which extends substantially over the entire length of the flexible tube (1).