Wide delay time (5 seconds to 2 hours); Over-ride switch for emergency operation Low voltage shut down; high voltage shut down Reverse polarity protected LED indicators for on, off and timing Rugged ABS case with screw hole mounts The Lind SDT1230-057 Shut Down Timer protects your vehicle's battery from over discharge and equipment from low voltage and high voltage damage. This device turns off electrical loads at a preset time after the car engine is shut down. The unit protects your vehicle battery and communications equipment from over discharge, low voltage and high voltage damage. Lind Electronics, Inc. reserves the right to limit or restrict the sale of its Shut Down Timers to any party for reasons unspecified.