GURU® Flag and Key

Price: Contact us for purchase info: (877) 379-8258


Product Description

The GURU® Flag and Key tool works in conjunction with the anti-tampering valve’s domed cap. This tool allows you to insert the key into the cartridge end of the valve after warming the nose of the cartridge. The valve resetting stem is not accessible, eliminating the ability to leave a penny or washer tucked up under it.

GURU® Flag and Key Product Sheet
GURU® Flag and Key Installation and Maintenance Instructions


  • Allows refilling of locomotive with cool water without tripping of GURU® Plugs
  • Alerts to the presence of deactivated GURU® Plugs
  • Minimizes risks of deactivated GURU® Plugs
  • Eliminates ability to tamper with the valve resetting stem
  • Can be used with Magnum and DL 2.1 Plugs

Design Features

  • Magnetic base attaches to locomotive body or running board
  • Flashing light for increased visibility
  • 3 lanyards for easier maintenance
  • Long cable length for easy placement
  • Quick release pin inserts into dome GURU® cap to eliminate tampering abilities


The key at the end of the cable is inserted into the cartridge end after warming the nose of the cartridge. The flag can then be attached to the side of the locomotive by its magnetic base to provide an external indication that the GURU® has been disabled. When the locomotive’s cooling system is back up to temperature, the key is easily removed and the GURU® is again armed to protect the locomotive.


The GURU® Flag and Key allows refilling a locomotive cooling system with cold water that would otherwise trip the GURU® Plug open. The GURU® Flag is a highly visible indicator that the key is inserted and the GURU® Plug is deactivated. This will help to prevent leaving the key in the valve resetting stem, defeating the valve’s function and possibly resulting in freeze damage to the locomotive.