This listing is for Reusable Silicone Mixing Cups. They cups are made from silicone and are designed for you to be able to reuse these cups over and over and eliminate wasted cups. The cup has flexible sides that allow you squeeze the sides together to aid in pouring. Once the resin cures you can flip the cup inside out which allows you to clean the cup completely for the next pour.
I have used these a few times now and love them! They aren't as rigid as most silicone cups which took a little bit to get used to but it actually makes them insanely easy to clean. I'm actually ordering more I liked them so much.