This is a Hybrid Racing oil cap.
The design of the oil cap was inspired by fuel doors used in the aerospace industry, and it has a clean look, maximizes hood clearance and is extremely easy to remove, expressing functional beauty.
The slim and fresh shape fits all HONDA engines.
It is introduced on Ameblo's "M&M HONDA's Honda Honki."
https://ameblo.jp/mandm-honda/entry-12796412648.html
https://ameblo.jp/mandm-honda/entry-12732740389.html?frm=theme