A steering wheel cover includes an outer layer and an inner layer. A vessels having a preformed grooves in the viewing surface is optimally designed for cell alignment and imaging. Distributing the removed infrared LEDs over a large surface ensures that the infrared radiation source ensures sufficient safety for the eyes, thus largely excluding the possibility of damage to the eyes of other road users. Said base parts are closed by a lid which is configured such that each base part and the lid form a test chamber for receiving the sample. The functional mode may include activating a user interface of the radioterminal.