Customer service hotline: 4000-17-2117

Yung-Yi Technology (Shanghai) Co., Ltd. ( Operations Headquarters)

Yoi Technology (Shanghai) Co., Ltd. (Operation Headquarters)

Shanghai Yongyi Instruments Co., Ltd.

Shanghai Yoi Instruments Co., Ltd.

Room B1104, No. 650, Xinzhuang Road, Caohejing Development Zone, Songjiang District, Shanghai

Telephone: +86-021-5169-8055 (Ms. Shi)

Mobile: +86-138-1781-3087 (Mr. Li)