Here's the complete list of features:

• Protect your Commodore 64(C/G/GS/Aldi), Commodore MAX, Commodore VIC-20 CR, or Plus/4 (with an adapter) from overvoltage on the 5VDC line.
• 5VDC and 9VAC Barrel connectors to allow easy use of alternative power sources. 5VDC barrel input is also protected from overvoltage.
• Use an external 5VDC power source and continue using your Commodore power supply for 9VAC even when its 5VDC has failed.
• Designed to handle 3 Amps in order to protect and power your system.
• High quality relay that disconnects both DC and AC lines in the case of an overvoltage condition.
• Dual color LED indicating the 5VDC status: Normal (Green) or Tripped (Red)
• Can be reset with the recessed reset button or by unplugging the power source.
• LED indicator shows when voltage is safe or tripped.
• Four possible trip point settings to customize the protection to your system.
• A high quality aluminum enclosure with factory cut openings. The case is quite small at around 2.5 Inches Wide by 2.8 Inches Deep and 1.5 Inches tall.
• 3M Rubber Feet and a professionally printed SaV64 logo are also included to complete the device.