This, alarmingly stylish, document was produced by Theilig in the DDR (East Germany) in the grim-grey-Stalinist-concrete 1950s. It depicts a chain tensioner that later came to be called the Spannfix.

A few years later, using much of the same 'product design language', Theilig produced a derailleur system called the Schaltfix.

• Publisher: Theilig
• Country: Germany, although this leaflet came from what was the DDR at the time
• Date: 1953?
• Derailleur brands: Theilig
• Derailleurs: none