This German PAK 36 anti tank gun is on display at Military History Museum of Seville, Spain. It's a rare piece in Spanish Military Museum. 

It went into production lines in 1933, going on until 1941. The design was attractive and was copied by the United States, Japan, Italy, Holland and Russia which would be replaced from 1942 by 45 mm. cannon Mod. 1942. As anti-tank weapon of Wehrmacht infantry units,  it was followed in this role by the 5 cm Pak 38 gun.

This small antitank gun was manufactured by Rheinmetall-Borsig resulting in a slight piece, weighing 432 kg., just with a pair of tires for transport and a 4 mm. armored shield enough to protect the crew from rifle and shrapnel. Its armour piercing capability was limited to only 48 mm. at distance of 500 meters. The weapon could fire at a very fast cadence; up to 15 rounds per minute.

Specifications:

• Caliber: 37 mm. L/45.
• Length: 1.66 m.
• Width: 1.65 m.
• Height: 1.17 m.
• Weight: 432 kg. (Transport).
• Projectile weight: 0.68 kg.