It is good as a shaker. It has a measuring cup and an extra container underneath for supplements, which can be removed if you don't want it. It also has an internal mesh (plastic net) to prevent protein pieces from passing through the mouth, which did not dissolve well. However, it has a significant drawback: the lid does not close easily, you have to press it with force. I admit that I struggle every time. Of course, as long as I have been using it, especially when shaking, no liquid has leaked from inside. It seals very well.
Update 6-1-2023. The lid does not close properly no matter how tight I screw it, resulting in droplets flying out when shaken. I have never used the container underneath.