An inventive medical system has a housing with a first guiding surface. A preassembled module is received in the housing. The module includes electronics electrically connected to an analytical sensor, an insertion component configured for inserting the analytical sensor into body tissue of a user and a sterility cap at least partially surrounding the insertion component. The module has a second guiding surface. A protective cap is removably connected to the housing and covers the preassembled module. The protective cap is removable from the housing by pulling the protective cap from the housing. The first guiding surface guides the protective cap during the pulling of the protective cap from the housing and the second guiding surface guides the sterility cap during pulling the sterility cap from the insertion component. The length of the first guiding surface exceeds the length of the second guiding surface.
