LoRad Shielded Mains Blocks in Aluminium 
The mains blocks are fully shielded from radiated electric fields by means of their aluminium chassis. The conductive chassis drains the interference down to ground. It has to be connected to an earthed socket with an earthed mains cable, in order to work properly. For a useful degree of shielding and immunity, the mains block should be combined and employed with SUPRA LoRad shielded mains cables. 

SUPRA NIF Transient Filter 
All models are equipped with SUPRA NIF (Non-Intrusive Filtering), a mild transient filter which will not influence the transient properties of the equipment. SUPRA NIF is developed by Ben Duncan Research in England.

3-Way Surge Protection
The SP-models, i.e MD06-BS/SP, MD06-EU/SP and MD06-US/SP, are all equipped with SUPRA’s surge protection device which protects all three ways: Live to Earth, Neutral to Earth and Live to Neutral. Many other surge protectors are only Live to Neutral, and do not protect against field surges by proximate lightning. Lightning is always referred to earth.
For a correct and safe 3-way surge protection, the mains block has to be connected to an earthed wall socket.