It has been recently found that some Tronix SpeedFire cables (cable that connects the flash gun (speedlights) to the Tronix SpeedFire) have grounding problems that cause unsafe operation. In order to prevent any potential or further accidents, we are requesting ALL Tronix SpeedFire users (Tronix SpeedFire for Canon and Nikon) to contact us and we will ship replacement cables. In the meantime, we strongly urged users not to use your Tronix SpeedFire units and once replaced, the OLD CABLES MUST BE DISPOSED/THROWN AWAY. Please use the request form below. The replacement of cord is being done as soon as your request is received. The replacement of cable also serves as an upgrade to the incompatibility of Tronix SpeedFire to double AC sources. (See prior customer service advisory here .) For more info, click here .