TG is a gas-insulated high voltage current transformer based on a top-core design, able to withstand current up to 4,000 A and designed for voltages from 72.5 to 800 kV. Primary and secondary windings are located inside the upper part of the transformer. Some important features of the product are:
- Suitable for both metering and protection
 - Short primary conductor with low thermal losses suitable for high rated current
 - Magnetic cores made of laminated steel with oriented grain and a high level of permeability
 - Windings made of electrolytic copper
 - Safety margin for normal wind loads, stress from conductors and seismic forces
 - Remote control of the internal insulation level by means of pressure gauge provided with an alarm threshold and lock threshold
 - A pressure relief device protects the apparatus from internal overpressure