Alongside the Standardpanzer program, development of lighter vehicles was started in the early 1960s. During the design phase, multiple variants of power units, suspensions, and crew placements were considered. The common feature in all these projects was an oscillating turret with an unusual construction. The project was discontinued at the drafting stage. However, one of the variants with the oscillating turret and the improved Leopard 1 chassis saw production and passed trials.