The lowest power category in the 1925 German Round Flight for light aircraft was up to 40 hp. Hans Klemm thought this disadvantaged his Daimler L20, which had a 20-hp Mercedes F7502 engine, and improvised the L21 with two of these. Two L21s were built, D-623 flown by Bruno Loerzer winning the rally, and D-622, flown by Friedrich Siebel during the event. The photo was probably taken in 1925. The L21 was not pursued further since it could not maintain altitude on one engine. Klemm started his own company in 1927, and his partner Siebel did the same in 1937. Location not known - perhaps Daimler airfield at Sindelfingen. Photo from: Daimler