These YHDC micro current transformers can measure current up to 20A, and fit around wires that are up to 6mm in diameter. They are only 1.9 x 1.6 x 2.9cm, and have custom 3.5mm jacks which plug directly into our power meters. A TVS diode is built in for safety, and to prevent open circuiting. The output is 25mA, when the current is 80A.
These are highly recommended if you are monitoring a lot of individual 15A circuits in a panel and do not have a lot of space. These are the smallest current transformer that we carry. If you need to measure more current and want a smaller CT than the SCT013, the SCT010 can measure up to 80A.