- Nippon Seiki(NS) introduces Defi, a set of state of the art advanced motor vehicle performance monitoring products. Defi, which is French for challenge, is the brand name of Nippon Seiki. Life is full of challenges. With our ability to constantly produce new and innovative products, a challenge is something we look forward to. Defi-Shop terminated on-line shopping. Thank you very much for your ...www.defi-shop.com