I think your missing the point.
The secondary socket doesnt have a cap, but does have a connection back to one in the master. This can happily remain connected on the majority of installs. For the purposes of phones ringing, it doesnt matter if this is connected or not if you are using a compliant ADSL filter.
The secondary socket doesnt have a cap, but does have a connection back to one in the master. This can happily remain connected on the majority of installs. For the purposes of phones ringing, it doesnt matter if this is connected or not if you are using a compliant ADSL filter.