MyVolts 12V power supply adaptor compatible with Yamaha PSR-21 Keyboard - US plug This 12V high-quality power supply adapter serves as a replacement PSU for the Yamaha PSR-21 Keyboard. The adaptor features overvoltage, overcurrent and short circuit protection to protect it from damage. Package Includes: - 12V 1A US Power supply only ; This is a fixed voltage 12V power supply adaptor designed to meet exactly the power specification of your device. Lifetime warranty - this power supply comes with a warranty covering up to the lifetime of your device, or 10 years - whichever is greater. Energy efficient - this power supply is Energy Star level 5 approved, guaranteeing more efficient delivery of power to your devices, at less cost to you.