Not very exciting, but I would like to try and find out about them.
Rim 11.5cm dia., base 10cm dia., 4.75cm high. Smooth on the outside, textured inside. The textured effect reminds me of a golf ball/honeycomb.
Very curious about the slightly raised, wavy lines in a circle around the base, as I have not seen this before, but it was hard to capture in a photograph.