YTTW - The outer surface of the fire-proof cable is welded rolled strip of copper strip. The inner core insulation of the cable is wrapped by fire-resistant mica tape. Finally, the cable is made of glass fiber or other fire-resistant fillers.

BBTRZ--防火电缆和上面结构一样，就是把耐火云母带换成了陶瓷化硅橡胶带，这两种绝缘不同的电缆我也不知道哪种更好。

BBTRZ - Fire-proof cable is the same as the above structure, which is to replace the refractory mica tape with the ceramic silicone rubber tape. I don't know which of the two different insulated cables is better.

NG-A--防火电缆外护套用的是铝，也就是由铜带纵包焊接轧纹变成了铝带纵包焊接轧纹，里面的缆心可能会多绕几层耐火绝缘带。

NG-A - The outer sheath of fire-proof cable is made of aluminium, that is, from copper strip longitudinal cladding to aluminium strip longitudinal cladding. The inner core of cable may be wound by several layers of fire-resistant insulating strip.

BTLY--防火电缆外面的保护采用连续挤压铝管，里面缆心的保护也同样是连续挤压包覆的铝管，电缆里外的铝管保护都是光杆，没有轧纹，这种电缆的弯曲性能肯定是没有纵包焊接然后轧纹的柔性防火电缆。

BTLY - The outer protection of fire-proof cable adopts continuous extruded aluminium tube, and the inner protection of cable core is also continuous extruded coated aluminium tube. The inside and outside protection of aluminium tube of cable is smooth rod, without rolling lines. The bending performance of this kind of cable must be flexible fire-proof cable without longitudinal cladding welding and rolling lines.

BTTZ--矿物质绝缘电缆，也有人叫它氧化镁电缆，这种电缆应该是防火性能比较好的电缆，但是生产工艺非常复杂，主要是氧化镁粉的灌装比较难做 ，生产这种电缆的设备还不能实现国产化，主要靠引进先进技术和设备。

BTTZ-mineral insulated cable, also known as magnesia cable, this cable should be fire-resistant cable, but the production process is very complex, mainly the filling of magnesia powder is difficult to do, the equipment for the production of this cable can not achieve localization, mainly by introducing advanced technology and equipment.