1. Queyou: One of the world's largest automatic mahjong machine production bases, an enterprise dedicated to product design and manufacturing in the field of mechatronics, Matsuoka Electromechanical (China) Industrial Co., Ltd.

2. Xuanhe: One of the authoritative domestic companies producing fully automatic mahjong machines, an outstanding manufacturer in the field of professional mahjong machines, a well-known brand in the industry, Zhejiang Xuanhe Electric Co., Ltd.

3. Zhongyou: A professional fully automatic mahjong machine manufacturer integrating production, sales and service, one of the top ten mahjong machine-mahjong table brands, Hangzhou Zhongyou Mechanical and Electrical Co., Ltd.

4. Quesheng: One of the well-known manufacturing companies in the domestic mahjong machine industry, one of the top ten brands of mahjong machines, well-known in the industry for its strong technical strength, Zhejiang Queyou Technology Development Co., Ltd.

5. Songle: one of the leading manufacturers of mahjong machines in China, engaged in the development and sales of mahjong machines in China, a famous trademark and leading brand in Wenling City, Zhejiang Songle Mechanical and Electrical Co., Ltd.