What is the difference between 2D Mask and 3D Mask?

There are two types of KF94 masks, the 2D style and 3D style.
The 2D style is a clam shaped mask that is folded in half. (Horizontal)
While the 3D style is a mask that has two flaps that fold out to cover the nose and chin.

It is commonly referred to as a boat shape. (Vertical)

Examples

• 2D: ETIQA, Blue 2D, Korea Mask Small
• 3D: Blue 3D, Ilwoul, Korea Mask Large/Medium, Dr.Puri, Bluna