They’re one of the standard wide mouth styles for smaller volumes. and that’s exactly what they’re for.
We have a bunch around for green beans, they’re also great for sliced cucumber pickles.
I have mostly seen them in craft stores and cheap home decor place. Though they carry them at Target sometimes and at my local hardware store.
As some one else noted they aren’t meant for canning. So they’re a bit less available than other sizes.
