These are the MagbandZ
Designed in Richmond Virginia, by 5 Second Firearms https://www.5secondfirearm.com/
These are the latest and greatest solution to everyones magazine identification problems!
MagbandZ are the reuse-able way to distinguish between the various calibers you might have.
Calibers: .223, 5.56-LAP, 6.5, 300, 300-sub, 7.62, 6.8 SPC