We have achieved an extremely lightweight aluminum oil filler cap (unit weight: approx. 60g) by reducing the thickness to the utmost while ensuring sufficient strength. In addition, we have adopted a shape that allows easy finger grip, making opening and closing the cap extremely easy. Some car models such as FD2 have a layout where the shaft passes directly above the filler cap when a third-party front tower bar is installed, and it may be difficult to open and close the filler cap, but insert a round bar etc. into the filler cap cutout hole. It can be opened and closed relatively easily by inserting it. The functional design achieved as a result of this pursuit of practicality is perfect for dressing up the engine room. Four body colors are available: red, black, gold, and shiny silver.