Current transformers scale the large values of current to small, standardized values for measuring purposes. They provide a secondary current that is accurately proportional to the current flowing in its primary circuit. The current transformer presents a negligible load to the primary circuit. 

The length of the CT clamp's cables is 60 cm. 

*NOT compatible with Shelly Pro EM-50, Shelly Pro 3EM, Shelly EM Gen3 and Shelly Pro 3EM-3CT63