The item is used in connecting a light fitting or other device to the network supplying it. The counter coupling in the fitting is either NAC31.W or NAS31.W fitted in the device by the panel mounting adapter NK3P.W. The T-connector is fed with a NAC32S.W -coupler (or with an installation-ready cableset, where the NAC32S.W is coupled). The installation continues from the T-connector to the next device with a NAC 31S.W (or with an installation-ready cableset, where the NAC 31S.W is coupled).