Source:
https://scmp.com/article/494383/how-choose-sandpot

How to choose ... a sandpot

If you go into any neighbourhood kitchenware or hardware store, chances are you'll see an array of rough pots lined up against the wall, almost always with a bucket of water nearby. These Chinese sandpots (sometimes called clay pots) are excellent, inexpensive cooking implements.

What do they look like? Pale, sand-coloured on the outside with a dark brown, shiny interior. They come in different shapes - the most common are narrow on the bottom and wider at the top, or squat (but sometimes tall) and roughly barrel-shaped (thick in the middle but narrow at the bottom and top). Sandpots always come with lids, and they usually have a handle off to one side. The pots are sometimes reinforced with wire wrapped around the exterior and most of them have a small hole on the lid, which lets steam escape.