Modular controllers for fighting games range in their specifications. However, a common element is that you can modify their usage style on the go.
The X1 is Haute42's first attempt at a modular design, with the WASD buttons being rotatable and even replaceable with a joystick!
The Atachon Angel has split wings that allow you to set the sides of the controller farther apart than usual if you want.
The Victrix Pro KO features up to 16 moveable buttons in a layout that was optimized by the fighting game veteran, Momochi.
The Carnage Guisada Alpha is available in different sizes, layouts, and materials so you can choose what resonates with your style.
The BnB Gen 3 has a modular design that allows you to switch between top panel layouts without needing to buy a whole new case.
With the Meisterbox L, Alpenmeister offers a unique way to play Street Fighter (and other fighting games), such as through a split layout.
The Mu-1612 is a 15 button stickless controller made of aluminum, and it features a split PCB layout for modular upgrades.
Remember the banned GafroBox? Well, Gafro released LI.TERAS, which brings back the same goodness—plus interchangeable modules.