Abstract: A rotatable locking member is located between a plunger of a switch and a contact part that is configured as a slide, with the rib-type locking elements of the locking member engaging corresponding groove-type locking elements of the plunger. The contact part is fixed in the axial direction on the locking member, but is mounted so that it can be rotated in relation to the member. In an initial position of the plunger, an anti-torsion device, which can be released by an unlocking action, secures the locking member against torsion. This allows both the plunger and the contact part to be accommodated by the housing of the switch so that they can be axially displaced, but are resistant to torsion, thus increasing the adjustment reliability and preventing undesired torsion of the locking member before the start of the adjustment process.