TDO (Telefonsteckdose) is the telephone plug used by A1 Telekom Austria.
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plug
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socket
![](http://upload.wikimedia.org/wikipedia/commons/thumb/4/42/Schematics_of_Austrian_Telephone_Socket_TDO.svg/220px-Schematics_of_Austrian_Telephone_Socket_TDO.svg.png)
The sample here has 6 conductors (of a possible 10), 2 on one side (visible in picture) and 4 on the opposite side. Connector dimensions are 3mm x 18mm (includes top latch).