1Main Function: The top post knife blade master switch is used for battery to isolate and secure the electrical system, eliminate any power draw from the battery when vehicle or boat is not in use, disconnects the battery safely. 2Durable Construction: Made of premium plastic and brass materials, this battery top post disconnect switch is built to withstand rugged use and rust, durable and reliable, ensuring long lasting performance. 3Easy to Use: Simply flip the switch to turn the power on or off, allowing for quick and effortless control of the battery connection, effective and convenient to use. 4Versatile Application: This battery disconnect switch can be used as a replacement in various car models, RVs, ATVs, and boats, offering a reliable and effective way to protect and disconnect the battery. 5Ideal Replacement: battery knife blade shut off switch is a perfect replacement for repairing, can directly replace the old and broken accessory, ensuring the normal operation.