Small DC/DC modules exists, but this one is mainly made for my own usage as I needed a DC/DC to use with decent voltages and small size was involved. It has the design and size of a TO220 making it excellent for breadboard usage.
The design is based on LMR14206 from TI that handle input voltage from 4.5V to 42V, output voltage from 0.765V to 34V with 0.6A output current. Voltage can easily be adjusted to any value by changing resistors and output current is sufficient for a lot of applications.