The invention relates to a medical injection device having a polymeric housing or housing parts. The housing comprises a moulded outer housing element and a moulded elongated tubular inner housing element. The elongated tubular inner housing element is formed as one unitary element and carries a pointer and one or more projections in predetermined and correlated positions. The pointer points to indicia on a scale drum and the projections engage the scale drum. The outer housing element is moulded over the elongated tubular inner housing element in a 2K moulding to form one single housing component.