Cyrillian transport

The Cyrillian species of the planet Cyrillia began using floating turbine powered transports on their homeworld sometime prior to the year 189 BBY. The species designed the DUM-series pit droid in order to perform maintenance on the transports, including specifically jobs requiring small size, such as moving under hovering vehicles or climbing into circuitry bays.

Behind the scenes
The Cyrillian transports were first mentioned in the DUM-series pit droid entry in The New Essential Guide to Droids, a reference book written by Daniel Wallace and released in 2006.