Review on Charging Blocker Charger Protect Against by Guerdon Draper

I verified this by plugging in a flash drive and copying the file to it. I then removed the drive, connected the data blocker and connected the drive to the data blocker. The computer didn't see the drive, I couldn't copy to it or see the files on it. To me, this shows that it's not letting data pass through the data blocker. I'm not sure how else to test this. As far as I can tell, this provides the necessary protection. Then I connected the device for charging and the data blocker allowed charging. So it's working again.