<p>The pipette (1) has a pin coupled with a selection wheel (10) and arranged on a covering. The selection wheel is adjusted outside of a bar housing (2). The covering comprises a cover element at which the pin is arranged and another cover element at which an incident edge is formed. A relative position of the incident edge is adjusted in a longitudinal direction of a shaft. An eccentric cam part is arranged on the covering and fixes the cover elements relative to each other in the adjusted position. The cover elements are made of plastic and metal sheet. The cover elements are in form of an elongated hollow body and a strip.</p>
