12 x Stainless Steel Sauce Cups by Winco.  I keep similar stainless steel portion cups in my Brew Day Box and use them to portion out hop additions and other boil additions and for pH and gravity sample containers.  These are a great size and don’t take a lot of room since they nest together.

Stainless Steel 2.5 Oz. Sauce Cup (Pack of 12) – note that multiple variations of this product may be available, as such a different version may appear at this link