This article covers two types of double steel tape armored flexible cables: Rvfv-K and Rvfav-K, with a conductor cross-sectional specification of 240mm² and flame-retardant properties.​ The 240mm² conductor cross-section endows the cable with a strong current-carrying capacity, usually reaching 400-500A, which can meet the power transmission needs of large industrial equipment and high-load power distribution systems. The flexible design makes the cable easier to bend during laying, especially suitable for narrow spaces that require turning, such as internal wiring of equipment and underground pipeline threading. The double steel tape armor layer significantly improves the mechanical strength of the cable, which can resist external extrusion, collision and other impacts, and protect the internal core from damage.​ Flame-retardant property is an important advantage of this type of cable. When in contact with fire sources, it can inhibit the spread of combustion and reduce the release of toxic smoke, buying time for personnel evacuation and fire fighting. Therefore, it is suitable for places with high fire safety requirements such as high-rise buildings, subways and power stations.​ There may be differences in structural details between Rvfv-K and Rvfav-K models, such as fine adjustments to insulation or sheath materials, but both take "double steel tape armor + flexibility + flame retardancy" as the core design, balancing transmission capacity, protection performance and installation flexibility.