 This enabled all stations in a net to be confidently pre-tuned on the same channel and eliminated the old compromising "Tuning and Netting Call" system that advertised the presence of activity to an enemy.All the sets were constructed in strong hermetically sealed alloy enclosures - a measure that had been found to be essential to ensure durability and reliability during the previous war, and were sized to fit a standardized range of vehicle mountings.A range of control and distribution accessories known as a harness to enable radio facilities to be accessed from various points in a vehicle was also produced.