The visible telephone and visible doorbell have wide application and bright prospects. The electron gun is one of the key components of the picture tube for visible systems.
可视电话、可视门铃具有广阔的发展前景，其显像管电子枪属于关键部件。
The visible telephone and visible doorbell have wide application and bright prospects. The electron gun is one of the key components of the picture tube for visible systems.
可视电话、可视门铃具有广阔的发展前景，其显像管电子枪属于关键部件。
应用推荐