No lock switch:It means that the change will soar routinely when pressed Without mechanical lockingSelf locking switch:Press as quickly as &;&;ON&;&;Press as soon as &;&;OFF&;&;Product ParametersProduct Name: Push Button SwitchProduct Withstand Voltage: AC250V(50Hz)/minTemperature Range: -40°C~70°CPress Force: 250 soil 50gRated Load: DC12V zero Electronics:> 100MΩContact Resistance: ≤200MΩService Life: ten thousand occasions (times)