Tianjin yining technology co., ltd
Tianjin heshang Hongfeng technology co., ltd
Tianjin haoyuan information technology consulting service co., ltd
Xiyue Information Technology (Tianjin) Co., Ltd.
Tianjin citizen bang network technology co., ltd
Tianjin Zhong Jian Daxing Science and Technology Development Co., Ltd.
Many other companies also sell medical masks. You can look at the list of medical mask units in Tianjin, which has detailed information.