YMW68-20 multi-step selection switch is of all-purpose,used widely in the power supply of CNC control panel and others. The power supply switch is working under high voltage, large current, so it need ag alloy contacts, but in CNC panel it is low voltage and low current, consequently it shall require common alloy, due to their difference,it shall be classified clearly. Many products are not indicated the difference legibly. Nalurally it will resuit in lots of damage and bad contact. Notwithstanding this problem. We still developed the multi-step selection switch YM68. applying blue and white colors to idenitify the high voltage and current. Low voltage and current. This is to improve the working life.