In the context of gaming chairs, "2D" armrests typically refer to armrests that are adjustable in two dimensions: height and horizontal position.

Height Adjustment: 2D armrests allow you to adjust the height of the armrests up or down to accommodate your preferred arm position relative to your gaming setup or desk height.

Horizontal Position Adjustment: 2D armrests usually offer some degree of horizontal adjustment, allowing you to move the armrests closer together or further apart based on your shoulder width and comfort preferences.

These adjustments can be beneficial for users to find a more ergonomic and comfortable position during long gaming sessions, as they can customize the armrests to better support their arms and alleviate strain on their shoulders and wrists. However, it's important to note that 2D armrests do not typically offer adjustments in other dimensions such as depth or angle, which are features found in higher-dimensional armrest designs like 3D or 4D.