Fits fine to a half-size breadboard

As already described, one needs to program a serial TTL Converter to the module.
The pin header you have to turn yourself soldering. On the back, it is labeled with Deek-Robot.
There are different versions of the boards offered with 8- and 16 Mhz. In contrast to
Arduino Uno but there is no voltage transformer on the board, thus missing a 3.3V pin.