KB0 is used as a main switch and equipped with different boxes to form XBK1 protective control boxes having various protective degrees such as IP 40, IP 54 and IP 65, intended for control and protecting of outside and individual loads. Switches, rotary handles, push buttons and indicators can be equipped on the front panel of the boxes. With its compact size, light weight, reliable and safe operation, easy wiring and higher protective degrees, it is available either for local control, or remote control, or both. The main switch KB0 equipped with different protective box bodies can make up multi-level protective control box of IP40, IP54, IP56 protection level, which is suitable for control and protection of outdoor and remote independent load. KB0, KB0-F, KB0-G, KB0S, KB0N, KB0J, KB0Z and KB0R can combine various modes like single-circuit and multi-circuit; the panel of box body can be equipped with selector switch, knob, button and signal lamp according to requirement. Compared with various traditional protection boxes and composite electromagnetic starter, it owns advantages of small volume, light weight, safe and reliable operation, convenient connection and high-level protection etc, it can be operated by either local or remote control or both local and remote control mode, and it’s the best choice instead of traditional product.