The resulting Jumo 211 was first prototyped at Jumo's Dessau plant in 1935 and started testing in April 1936. Like the 210H, it featured a mechanical direct fuel injection system using small pistons driven off the crankshaft, three valves per cylinder, and an inverted V layout. It also had an open-cycle cooling system, working at atmospheric pressure.[1] Limited production of the 1,000 PS Jumo 211A started in April 1937 at Dessau, with just over 1,000 completed before full production was started at Magdeburg in July.[citation needed]