Notes: This is a 1960s-vintage MBT built and used by Switzerland. By 2000, all PZ-61s have been modified to PZ-61AA9 standard, with coaxial cannon replaced by a machinegun, better radios, radiological shielding, and an NBC overpressure system and lugs for reactive armor.

Notes: The PZ-68 is a progressive development of the PZ-61, with a more powerful engine, wider tracks, a larger turret, night vision gear, and laser rangefinder and improved gun stabilization. The layout is standard, with the driver at the front center deck, and commander and loader’s hatches on the turret deck. Unlike most tanks, the PZ-68’s turret has a cupola for both the commander and loader, and both have weapons mounts, the commander’s at the front of the cupola, and the loader’s at the rear of his cupola.

The PZ-68 base model stabilizes the main gun in the up-down axis, The gunner’s sight uses a coincidence rangefinder that has a magnification of x8, while the commander’s periscope also has a magnification of x8. The PZ-68 does include a 100-liter tank for drinking water. The PZ-68 Mk 2 gave the main gun a thermal sleeve and a fume extractor. The PZ-68 Mk 3 is the same vehicle as the Mk 2 but has a larger turret with more ammunition storage. The Mk 4 is similar to the Mk 3, but is from a difference production batch.

In 1988, the PZ-68/88 Upgrade was ordered. This gives the vehicle an automatic fire suppression system. The gun is fully stabilized, and adds a laser rangefinder. The suspension is upgraded and the vehicle is equipped with an NBC overpressure system.

Selected PZ-68/88s were up-gunned with a 120mm gun. This is an L/49 gun, as opposed to the L/44 of the standard NATO gun.