The Pz.58 was the first battle tank designed and built in switzerland, armed with a 90mm gun. The later Pz.61 adopted the British 105mm gun. The Pz 61 was the first tank produced in quantity in switzerland, the production order being for 150 tanks produced by the Federal Construction Works. The Pz 61 became the basis for other armoured vehicles, the first being the Entpannungspanzer or Entp.Pz 65.
