Certain aspects of the present disclosure relate to a telecommunication enclosure having a configuration that can be readily customized in the factory to satisfy customer specifications and can also be readily upgraded in the field. In certain examples, the telecommunication enclosure includes a main housing defining a plurality access ports. A plurality of different add-on components can selectively be coupled to the main housing at the access ports in sealed relation to the main housing. The add-on components can include visual indicators which are visible from outside the main housing when the add-on components are mounted to the main housing.