The armour was light, just enough to defeat light machine gun fire. The front side and back plates had a thickness of . Due to differences in angling the effective protection varied though: the back, sloped at about 30°, was the best protected area with a line-of-sight thickness of about 20 mm, to which a certain deflection effect should be added. The 45° front glacis had an effective thickness of about 14 mm; the sloping effect of the side plates was negligible. The top had a thickness of six, the bottom of five millimetres. Several conventional designs, the M36 and M38 included, did not even have bottom armour. The fenders too were made of armour steel, four millimetres thick. The Swedish turret had a lower armour basis: its walls were 7.5 mm thick, its roof five. The small size and light armour resulted in a relatively light vehicle with a loaded weight of somewhat over six metric tonnes. The pressure was evenly divided over the wheels, the rear axle bearing four and the front axle two tonnes. Additional protection was provided by two portable fire extinguishers, one of the dry powder type, the other using carbon tetrachloride.