Reverse Polarity Power Adaptor: Most adapters only have single polarity, positive (+) or negative (-) polarity. This SoulBay AC Adapter owns Dual Polarity, reversible and changeable. Versatile POWER SUPPLY: straightforward adjustment for All-in-one multi adapters and multi amp devices, solid and well built. Voltage range, connector jacks and polarity are Selectable. WIDE APPLICATIONS: for router, speaker, monitor, camera, smartphone, led strip, piano, keyboard, effect pedal board, and a variety of household electronics require 3 volt, 4.5 volt, 5 volt, 6 volt, 7.5 volt, 9 volt, 12 volt DC output with 2000ma load. Note: Not compatible with some Sensitive Electronics, such as AM/FM Radio. ) SAVES ON ADAPTERS: Own this adapter, you could use it for multiple devices and replace a lot old power adapters, savings on buying a new electronic device or extra original expensive power supply. PACKAGE INCLUDES: 1 x 3-12V multi-voltage ac adapter, 9 x changeable adapter tips, 1 x key and 1