Sweden was neutral throughout World War II, however they did sell some of their vehicles to countries before the war had started.
The first Swedish tanks were designed by Joseph Vollmer (he designed the German A7V, K-Wage, and LKI/LKII tanks) and were completed in 1921 and was called the Stridsvagn m/21. Only 10 were built and they weighed 9,700 kg. There was a male type with a 37 mm gun and a female type with two 6.5 mm machine guns. They had a Daimler 55 hp engine that allowed them to get a road speed of 13 mph (21 kph). In 1929 they had a 85 hp engine installed and became known as the m/21-29.
Landsverk company was formed in the late 1920s and developed a number of tracked and tracked/wheeled vehicles. The first tracked tanks were the L-5 and then the L-10, which were purchased by the Swedish Army and designated as the M/31. There was also the L-30 and L-80 which were wheel/track, the L-60 (some sold to Eire and Hungary), and the L-100 and L-101.
The L-60 was developed further and became the Strv m/38 in the Swedish Army. It weighed 8,500 kg, had a crew of 3, and had a 37 mm gun and 8 mm machine gun as the armament. Next developed was the Strv m/39 that had two 8 mm machine guns and a 37 mm gun.
The Jungner company assembled 50 of the Czech TNHS light tanks before World War II started. These were named the Strv m/37. It weighed 4,500 kg, had a crew of 2, was armed with 2 8 mm MGs, and was powered by an 80 hp engine that gave it a max speed of 37 mph.
The Svenska Flygvapnet (Swedish air force) was created in 1926.1 The early planes used were English and Italian.1 During World War II when Sweden wasn't able to import aircraft they designed and built their own.1 Saab was a primary manufacturer.1