Vandal-proof input devices and systems have spread to the most diverse areas of application. The operating characteristics are chosen for robust performance, and increasingly for aesthetic reasons too. Piezo switches are resistant to dirt, sand, dust and water; they will neither freeze nor stick through contact with fluids. These switches are especially suited for applications located in areas exposed to heavy snow and ice, including ticketing and toll machines, call boxes, building access controls, construction equipment, and transport vehicles.