4 Pack Reusable Overnight Oats Jars with Lid & Spoon, 16 oz Airtight Overnight Oats Container, Glass Mason Jars with Measurement Marks, Mason Jars On The Go Cups for Salads Yogurt Cereal Milk

The jars and parts are all of sturdy material and fit together well. I filled one with water and let it sit upside down for a few hours, then tilted a bit with the cover at the bottom, and no leaks at all.Each jar has marks for US fluid ounces (2.5, 5.0. 7.5, 10.0) and milliliters (100, 200, 300). The marks are part of the glass, they won't wash off. This made it easy for me to add oats and milk without needing a measuring cup, and 10 ounces of oatmeal is plenty for me. If you fill the jar up to the very top, it holds 14 ounces.I enthusiastically recommend these overnight oatmeal jars. They make my life easier and now I'm eating more oatmeal.

We all like the cups and very colors and nice design, great quality and material, great product and reasonable price.