The Weller W101 Line Voltage Soldering Iron has a power of 100W and a Voltage of 230V. The temperature of the iron is controlled by a built-in ‘Magnastat’ thermostatic switch. As magnets are heated, their strength reduces and this principle is used to operate a spring-loaded switch, turning off the power when a certain temperature is reached and turning it back on when the iron cools down. The operating temperature of the iron can be changed by swapping the soldering tip.