Having inherited the superior audio quality and foldable design of the treVolo, the first portable electrostatic bluetooth speaker, the treVolo S is even lighter and can be held in one hand. It provides users with a multi-layered listening experience by using the passive radiator technique to add richness to the bass, as well as the electrostatic diaphragm technology to deliver crystal clear treble and midrange. Furthermore, the NFC function enables users to complete bluetooth pairing simply by touching the device, and the included battery can last up to 18 hours.