HDT products of Cell phone signal jammer/blocker, coded safe, portable lighting system, smart-armory, Secrets-secured paper shredder and so on products have won us a great reputation in the filed of secrecy and security. Besides, all HDT products have been passed the certification authority of the State sector, with independent intellectual property rights. HDT products are widely used in various ministries, army and police departments. It is worth mentioning that the products line of 'Jing Cheng' has been classified as the recommended products of State Secrets Bureau. During the 16th, 17th and 18th National Congress of Communist Party of China, 'Jing Cheng' products were used as the information security devices and the excellent product quality and perfect after-sales services are highly praised by customers.