STS 24 Button Digital Display Speaker Phone. Rather than offering multiple phone models, Vodavi has packed all the features you need in one handsome, easy-to-use speakerphone. The STS phone has: 24 flexible buttons that can be programmed to monitor stations in useEnable one touch speed dial,or to enable system features such as Do Not Disturb, All Call Page, and many more 3 interactive soft keys positioned directly below the 2 x 24 character display that enable quick access to common system featuresThe phone is CTI capable as wellThe speakerphone enables convenient hands-free use and the volume control independently controls both handset and speaker volume