Adaptor made of brass which is then nickel plated in order to improve resistance to hard environmental conditions in which they are used. These end connectors, totally smooth and with a radial mouth, are used for branching from boxes without attachments or metal ducts in order to reduce internal clutter. Their use requires the use of female threaded connectors fitted on the conduit side. The thread is ISO Metric and complies with CEI EN 60423.