This silicone shaving bowl has flexible sides that allow it to collapse flat for travel/storage and expand for use. It's sturdy bottom has 11 agitators to help load your brush and/or build lather.
Bottom Interior Diameter: ~3.25"
Top Interior Diameter: ~4.25"
Extended Interior Height: ~2.125"
Collapsed Height: ~0.625"
A great resource showing the bowls and brushes: