You may be questioning exactly what the difference is involving 3D and 4D arms. 3D arms Have got a static condition, while 4D arms are adjustable. This means they can be moved up and down, forward and backward, or in some other blend of movement for optimum comfort and ease. https://archerbeaov.blogrelation.com/40521409/essentials-racing-style-leather-gaming-chair-no-further-a-mystery