Duna Sidecars
Manufactured in Hungary in the 1950s, it was specifically developed for Pannonia motorcycles. It was frequently mated to the Jawa.
Duna Models:
OK1: prototype
OK2: production began in 1955 and was restyled in 1957 and the suspension was improved.
OK3: introduced in 1959 and revamped in 1966 with a different shape to the nose of the sidecar body. Production continued until 1975.
The OK3 had a sleek design with integral mudguard and swinging arm suspension. It weighed 62 kg.
OK4: exhibited at motor shows but did not enter production
OK5: prototype
Sources: okteamclassic.com, pannoniafreunde.de.