The design language of Full card-case is "hollow out", which explored the relationship between inside function and appearance of the product. A slender hollow has been milled on the body to show the metal Refill inside. The shape formed the proper area for holding the pen, which find the balance between beauty and human engineering. Furthermore, Full weighs 19 grams, which provides good sense of holding to enhance its user experience.

Rongqi is a designer's own brand. The brand was founded in 2013. The brand set out to focus on the daily details of life, designing product such as office supplies, daily necessities and gift design and so on. There are two series of products: “hollow out” and “urban phantom”. So far, there are 6 products on the market. Many products participated in the crowdfunding of commercial platforms to obtain financing, and the cumulative sales reached more than 100 thousands dollars.