M8: primary current is small, and the capacity is 2.5VA and below for measurement or protection. It is mostly used in small spaces such as low-voltage drawer cabinets. Double M8: shell is made of flame-retardant and high-temperature resistant materials. The iron core is made of oriented cold-rolled silicon steel strip. The secondary conductor is made of high-strength electromagnetic enameled wire. The product has a novel structure, beautiful appearance and easy installation. The product has the characteristics of small size, light weight, high accuracy, large capacity, etc., suitable for small space places such as low-voltage drawer cabinets.