Reliable. Shenzhen Fan Fei Science and Technology Co., Ltd. is a company engaged in scientific and technological research. It is an officially certified company, which is within the scope of legal protection, so it is more reliable. Shenzhen, referred to as Pengcheng for short, is a sub-provincial city, a city under separate state planning, a megacity in Guangdong Province, a China Special Economic Zone approved by the State Council, a national economic center city and an international city.