This Pilna wiadomość icon is made in Material Design style developed by Google. This style is based on extremely simplified shapes, thin two-pixel lines, and is optimized for 24x24 px. Unlike other vector icon packs that have merely hundreds of icons, this icon pack contains 4,300 icons, all in the same style and quality.
An urgent message icon consists of a symbol of a letter, and next to the letter there is a circle with an exclamation point in the center. The letter is a rectangle shape had inside has lines to form a triangle that is folded over another triangle. An exclamation point is a line with a dot under it.