This bluetooth car visor speakerphone earned The Best rating by the Hammacher Schlemmer Institute for providing the clearest, unambiguous sound and the easiest handsfree pairing and calling. This model provided superior audio quality even at its lowest volume setting, unlike lesser models that experienced distorted communication. The easiest to use, it paired with a voice-activated cell phone using the command "Pair Me," eliminating the need to press and hold buttons for synchronization, unlike lesser models that require complicated button pushing. For cell phones equipped with voice activation, one's voice is all that is required for buttonless placing and receiving of calls using commands such as "Call Home" or "Answer." An included metal clip attaches to a sun visor; integrated magnets in the speakerphone's rear allow for quick attachment and removal. Provides up to 20 hours of talk time (up to 700 hours stand-by time) from a four-hour charge from USB or the included car charger. 4 3/4" L x 2 1/4" W x 1 1/2" D. (8 oz.)