A newly-made BT/GPO compatible 205 rectifier element, designed to prevent acoustic shock. The rectifier element connects between the T1 and T2 terminals and should be fitted wherever the rectifier is not present. The 205 rectifier was standard issue on GPO 746 telephones but may be absent on 706, 710 and 711 telephones. The rectifier diode element is not polarity sensitive, so can be fitted either way across the two terminals.
This rectifier is made without spade terminals to maintain low cost, it's designed to be twisted around the screw terminals using a small flat head screwdriver or long nosed pliers.