4000 Series button expansion modules are used to achieve the required amount of call buttons for audio or audio / video door entry systems. Modules are available with 2, 3, 4 and 5 buttons. Double button modules are also available with 4, 6, 8 and 10 buttons, where 2 buttons share the same name plate window. There are two variations of button modules available depending on the 4000 series audio or audio / video system being installed.
