DESC: No other ceiling speakers are as versatile, look and sound as good, or install as easily. A patent-pending two-piece twist-and-lock baffle-to-frame design allows quick installation and trouble-free upgrades or repairs. Niles award-winning, patented two-piece, no-strip speaker-wire terminal lets you make connections without having to strip the wire conductors. And because the connector is keyed, an in-phase connection every time is assured. An impedance-management system lets installers optimize electrical characteristics and match system design and associated equipment. Tone controls enable installers to fine-tune the sound after installation.