How long does the discs hold frequency?
The shelf life is 2 years due to the glue from M3, they can only guarantee the glue is good for 2 years
The discs themselves hold the frequency till it is consumed by the body so it is not the frequencies that determine the shelf life of the product.
We have a batch of discs from 8 years ago that we test now and then and they still work
Hope this answers the questions