For the transmission of call signals in TwinBus door intercom systems and video systems. Extra flat design, only 23 mm high. Differentiation between door and floor calls. 5 melodic ring tones. Volume adjustable in 4 levels. Call mute switch. Door opener function. Dimensions: 90x152x23 mm (WxHxD). Accessories: ==>UP frame 17322.. for flush mounting
