Standard is a round knob with your custom engraving. If you want a special cut out please specify that in your description. The photo for this product is just to show color.
Design your own custom bass knob dial. This will push fit onto any standard 6mm POT, used in all aftermarket controllers such as SPL Cartel, Slam Panda, PAC LC1 and most OEM amp controllers. The product image shows examples of the available color choices.