K6 and KR6 adjustable electro-mechanical pressure switch, with exchange contacts, are suitable for application where is not necessary to modify frequently the operating point. The regulation screw, interceptable with a 2mm hexagonal key in the executions “KR6” and K6/M3, is situated inside the instrument, protected by an upper cap or a connector against accidental manumissions. Concerning the execution “K6/M12”, the operating point can be pre-settled in factory, or in alternative the Customer can adjust the value removing the four screws on the top of the instrument.