Blister's marker jammer

Blister's marker jammer is a device used by Blister in the Yu-Gi-Oh! 5D's anime. It is a handheld device used to block a person's Criminal mark from transmitting a signal to Sector Security.

Fortune Cup
Blister uses this device on Yusei Fudo's criminal mark after he saves him from being followed Rex Goodwin's henchmen. It blocked the signal transmitting to one of the henchmen's Criminal mark tracker. However, its effects only last for a short while.