Gun dealer Matthew Hoover, who operated the CRS Firearms channel, was found "guilty of conspiring to transfer unregistered machine gun conversion devices that they referred to as "Auto Key Cards,"" the Department of Justice wrote in a press release. He was convicted of four counts of transferring unregistered machine gun conversion devices and faces 45 years in jail. 

Also facing severe jail time is Kristopher Justinboyer Ervin. The DoJ said he was convicted "of seven counts of transferring unregistered machine gun conversion devices, three counts of possessing unregistered machine gun conversion devices, and one count of structuring cash transactions to avoid currency transaction reporting requirements."

Ervin faces a maximum penalty of 110 years in federal prison. Sentencing for the two is scheduled for July 31. 

Hoover and Ervin sold lightning links, etched into metal cards, which he referred to as "Auto Key Cards," from around $40 for one version to more than $180. Hoover touted the cards on his YouTube channel.