Use this device is at your own risk. It can kill you!
Air tank certifications expire and they must be retested for safety purposes
Overfilling your air tank can be dangerous to your health.
Do not leave a tank unattended while filling.

This is the way I have been filling my air tank for years.  It's good for hand cramps as the Schrader valve reduces the air flow and causes it to take longer to fill.
The new improved way to fill the tank with an adapter fitting
Easy to make and simple to use
I took a male and a female threaded quick disconnect and fixed the two together.  Easy job to fill the tank now.