The FONE540 is a daisy-chainable USB speakerphone that enhances your audio conferencing experience in personal workspaces, huddle rooms, and medium-to-large conference rooms. Easy to plug in, install, and use, the FONE540 supplies business-class acoustics without creating extra work.Embedded with daisy-chain technology, the FONE540 can be expanded by adding up to two additional speakerphones to provide full coverage in all kinds of rooms. Both microphones and speakerphones can also be added to the system, making it a perfect choice in any space.