I also try to replace my Aerobikas and Aeroeclipse cups at the same time. Monaghan Medical recommends replacing the Aerobika every 12 months and the cup every 6 months. If you have multiple sets and do not use them daily, that could be factored in, but as far as I know, there is no guidance from the company on that. And yes, if you introduce new devices at different times, it is difficult to keep track of when they need to be replaced. I have heard of people marking them and even burning a symbol into them, but I have not done that.

Warm regards, Linda Esposito