Hm. 25: He 100

A German single-seat fighter aircraft designed for high-speed performance. It was considered one of the fastest aircraft of its time but was not widely produced due to production difficulties.

Hd-33 (Japan)

A Japanese heavy tank prototype developed during World War II. It featured a 75mm gun and thick armor, but it was never deployed due to production difficulties.

Hd-23 (Soviet Union)

A Soviet heavy tank prototype developed during World War II. It featured a 152mm gun and thick armor, but it was not adopted due to production difficulties.

Hd-9 (Soviet Union)

A Soviet heavy tank prototype developed during World War II. It featured a 122mm gun and thick armor, but it was not adopted due to production difficulties.

Gv. 5 (Type 5)

A Japanese light tank prototype developed during World War II, designed to be a more modern and powerful replacement for the Type 97 Chi-Ha. It featured a 57mm gun and sloped armor but was never mass-produced due to wartime production difficulties.

Daimler-Benz DB 2020 Engine

A powerful V-12 liquid-cooled aircraft engine developed by Daimler-Benz, intended for use in heavy bombers but facing production difficulties and limited use in combat.