By adding one further detail, Siedle has considerably upgraded the pass-through letterbox from the Siedle Steel design series and also responded to a wish frequently expressed by customers: the rear removal door for pass-through letterboxes is now also available in stainless steel, including the detachable chamber and rail. Now the appearance of the interior matches that of the exterior, with the quality of solid metal defining the entire system. The modified design makes it easy to adjust the surface level flush with the surrounding plaster by means of the variable removal door. This can also be fitted and relocated retrospectively. A surrounding seal affords protection against draughts.