Topic summary
Resonator ukulele

A resonator ukulele or "resophonic ukulele" is a ukulele whose sound is produced by one or more spun aluminum cones (resonators) instead of the wooden soundboard (ukulele top/face). These instruments are sometimes referred to as "Dobro ukuleles," however the term "Dobro" is currently trademarked by the Gibson Guitar Corporation.
The resonator ukulele is a descendant of the resonator guitar. The resonator guitar was originally designed to be louder than conventional acoustic guitars, which were overwhelmed by horns and percussion instruments in dance orchestras. A resonator ukulele is generally somewhat louder than a standard wooden ukulele, and has a different tone quality and distinctive appearance.
Though resonator guitars are often played flat in the lap steel guitar style, resonator ukuleles are almost exclusively played in the conventional manner.