A muffler unit for a general-purpose engine includes a muffler having a maze of sound-deadening chambers defined therein and an inlet pipe disposed inside the muffler. Preferably, the emulsion contains an oxygen binder such as hemoglobin, with which bound bioavailable oxygen, preferably together with other active substances, can be introduced into the skin by means of topical application, in order to support the cell growth of the stratum germinativum. The circuit board is disposed on the carrying part and has a circuit layer.