12 x Stainless Steel Sauce Cups by Winco.  I keep similar stainless steel portion cups – review– 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