This product consists of 2.5mm² and 4mm² BVR flexible copper core PVC insulated wires, specifically designed for building electrical systems, with excellent conductivity, flexibility, and safety performance. The conductor is made of high-purity electrolytic copper, stranded with multiple fine copper wires. The 2.5mm² specification is usually composed of 19 strands of copper wires with a diameter of approximately 0.41mm, while the 4mm² specification consists of 49 strands of copper wires with a diameter of about 0.32mm. The multi-strand stranded structure endows the wire with excellent flexibility, enabling it to easily adapt to complex corners, pipe threading, and narrow space installation requirements in building wiring. It is particularly suitable for line layout in concealed parts such as ceilings and wall interlayers, while reducing the risk of conductor damage caused by bending.​ The insulation layer is made of high-quality polyvinyl chloride (PVC) material, which has good electrical insulation performance, aging resistance, and mechanical strength. The PVC insulation layer can effectively isolate the conductor from the external environment, withstand the normal operating temperature range (-15℃ to 70℃), and has certain acid-alkali resistance, oil resistance, and flame-retardant properties. It meets the safety requirements of national standards such as GB/T 5023.3 for building wires, which can significantly reduce the hidden dangers of short circuits, electric leakage, and fires. The insulation thickness of the two specifications is reasonably designed according to the conductor cross-sectional area. The insulation thickness of 2.5mm² wires is approximately 0.8mm, and that of 4mm² is about 0.9mm, which not only ensures insulation reliability but also avoids excessive wire diameter increasing wiring difficulty.​ In terms of electrical performance, the rated current-carrying capacity of 2.5mm² wires is approximately 16-25A (depending on the laying environment), suitable for household lighting circuits, ordinary socket circuits, and small household appliance power supply. The rated current-carrying capacity of 4mm² wires is about 25-32A, which can meet the power supply needs of high-power electrical appliances such as air conditioners and electric water heaters, or be used as the main line of branch circuits. Both are applicable to building electrical systems with AC 50Hz and rated voltage of 450/750V and below, and are widely used in power and lighting line laying in residences, commercial buildings, office buildings and other places.​ The product comes in a variety of colors, including yellow-green (exclusively for grounding wires), blue (neutral wire), brown or black (live wire), etc., strictly following the color identification standards of electrical specifications. This facilitates distinguishing line functions during installation and reduces wiring errors. In addition, the copper conductor of BVR flexible wire has undergone annealing treatment, with a smooth surface and no burrs, making close contact with connectors such as terminals and sockets, reducing contact resistance and heating risks, and ensuring long-term stable operation. Overall, with its characteristics of flexibility, easy installation, safety, reliability, and strong adaptability, this series of wires has become an ideal choice in building electrical wiring, which can meet the power supply needs of different power loads and provide a solid guarantee for the safe and efficient operation of building electrical systems.