An electrical contact is provided for electrically connecting a connecting object to a printed circuit board, without the need of a housing. The regions of differential permeability may be provided by areas where the braided mesh density is greater or lesser than surrounding areas andor by means of a baffle. In a further embodiment of a method of controlling the flow of fluids through a microfluidic circuit according to the present invention, the microfluidic circuit includes first and second triggerable valves in parallel. The first transducer ring can use results related to the reflection of the transmitted first wave to guide a second wave along the pipe that is received by the second transducer ring. The system may also comprise various feeding devices configured to feed the stencil material from the laser cutting apparatus to the stamping apparatus andor configured to feed the impressionable material through the stamping apparatus. With the ventilator, the air pressure of the ventilator is increased and noise can be controlled.