We recommend to use only one type of product in a mixing cup.
For example if you mix Silicone Condensation 20 in this cup, you can no longer mix addition curing silicone in the same cup. If you would try, the addition curing silicone might be poisened and the cure will be inhibited.
The tight-fitting lid also tunrs this cup in a good storage container (kept in a dark space).
Tip: clean the cup only once the silicone is cured. This way you pull the silicone out in one go.