A secondary element with a first open end and a second end positioned opposite the first end has a filter medium arranged about a longitudinal axis of the secondary element and extending from the first open end to the second end. A closed end disc is disposed at the second end and seal-tightly closes off the second end. The closed end disc has a first connecting element that, for an intended installation of the secondary element in a filter system, is configured to interact with a second connecting element of a support tube of the filter system to secure the secondary element on the support tube. A filter system with such a secondary element has a support tube provided with a complementary second connecting element, wherein the secondary element is secured on the support tube by the first and second connecting elements engaging each other.