Comparison : Item # WSX050-4000, 5 Volts (V) Output Voltage (DC) and Positive Polarity Center Interchangeable Input Plug Wall Plug-In Switch Mode Power Supply
Item # WSX050-4000-R, 5 Volts (V) Output Voltage (DC) and Negative Polarity Center Interchangeable Input Plug Wall Plug-In Switch Mode Power Supply
Item # WSX050-4000-13, 5 Volts (V) Output Voltage (DC) and Positive Polarity Center Interchangeable Input Plug Wall Plug-In Switch Mode Power Supply
Item # WSX050-4000-R13, 5 Volts (V) Output Voltage (DC) and Negative Polarity Center Interchangeable Input Plug Wall Plug-In Switch Mode Power Supply
Item # WSX060-4000, 5.9 Volts (V) Output Voltage (DC) and Positive Polarity Center Interchangeable Input Plug Wall Plug-In Switch Mode Power Supply