2 Button. This Videx 3111 full base audio phone has an adjustable electronic call tone, a door open push button and a spare service button. It is suitable for use on traditional 4+1 audio systems that require an electronic call tone including the 4k series, 8K series, VR4K series and VR120DK series kits. . 3 position call tone adjustment. Spare service button. Door release facility. White finish