The present disclosure provides a flexible container. In an embodiment, the flexible container includes (A) four panels, each panel comprising a flexible multilayer film. The flexible multilayer film includes a polymeric material composed of a polymeric material. The four panels form (i) a body, and (ii) a neck. The flexible container includes (B) a fitment having a top portion and a base. The fitment is composed of a polymeric material. The base is sealed in the neck. The base has (C) a cross-sectional shape with a diameter (d), and the base has a wall thickness (WT). The base has a d/WT ratio wherein the d/WT ratio (in mm) is from 35 to 800.