Insert the soldering iron tip to the bottom until you hear a sound indicating the completion of this step. 2. Long press to turn on automatically 3. Press once to switch temperature The 3 temperature levels are a temperature range. They are not very accurate and have errors. Voltage 5V, power 8W This link has 3 different models, C200 and C200S and C201S C200: There is no digital display C200S: It has a digital display, an LED light on the head of the handle, and a switch button. C201S: It has a digital display, and a switch button. C201S STYLE