These plugs are typically used on SPAL and other high quality fans as well as some brands of electric water pumps. They are very difficult to find. If you’re building a harness for your electric fans or pump, they’re instrumental in its construction. We should note that we will build such harnesses for you if you elect. Contact us for more details.
You can also use these plugs for a simple and easy way to disconnect up to 10 AWG wires. We use them all the time, from neutral safety switches to electric water pumps. They work great and are easy to install!