The H-39 was an improved H-35, with a more powerful engine along with other modifications. The H-39 had a raised squared rear deck which differentiated it from the H-35.
The turret was produced by AMX and was identical to the R-35s and R-40s.
The engine was on the left in the rear and the gas tank on the right. An external fuel tank could be used as well as a skid tail to increase cross country performance.
Hull was cast sections bolted together.
The driver was in front a little to the right of center. He had a split hatch cover which one side opened upwards and the other opened forwards. There was an escape hatch in the floor.
The commander had a rear door on the turret that could be folded down horizontal to form a seat. He also had a cupola that could be traversed.
The 37 mm SA-38 L/35 was installed starting in April 1940. Some H-39s were updated when the SA-38 was available.
The SA 18 had velocity of 1,273 fps. Some had a 37 mm Sa 38 L/33 longer barrel gun installed (velocity 2,300 fps). The H-39 carried 100 rounds of 37 mm ammunition.