A. This is an automatic circuit breaker for audio system modification, specially designed for cars, RVs, yachts, etc. It can serve as a reliable helper for circuit protection. B. In terms of design, it is made of zinc alloy, which is sturdy and durable, effectively ensuring stable operation in various complex environments. There are multiple specifications available, including 30A, 40A, 50A, 60A, 80A, 100A, 150A, 200A, 250A, and 300A, meeting the diverse needs of different users. C. It has a wide range of applications and is suitable for general vehicle models. Whether it is a car or a boat, it can be easily adapted, with good versatility and compatibility. It can automatically restore power supply, playing the role of circuit protection and insurance, providing reliable safety assurance for your audio system and the entire circuit system, and helping to prevent device damage caused by circuit failures, allowing you to use it more confidently. D. This product is sold in regions such as Africa, Europe, South America, Southeast Asia, North America, Northeast Asia, and the Middle East, and its quality has been widely recognized. In addition, it has an authorized self - owned brand, further highlighting its unique value.