Since ancient times, the shield has been one of the most important weapons for human beings to protect themselves from threats. From the era of cold weapons on the battlefield, soldiers holding heavy wooden or metal to build a big round shield to cover each other's charge; to today's police forces often wear lightweight tactical small square screen to resist attackers throwing objects... This history of change across thousands of years is the topic we are going to explore together today.

With the progress and development of science and technology, modern shields have already got rid of the shackles of traditional single material and moved towards diversification. For example, high-strength composite fiber materials are widely used in police equipment because of their excellent toughness and low density, which not only ensures sufficient fighting capacity but also reduces the carrying burden. The aluminum alloy frame structure has become an ideal choice for many professionals, taking into account the two advantages of rigidity, firmness and moderate weight.

However, not all shields are tailored for the same purpose. For law enforcement officers, what they need is professional-grade products that can be deployed quickly in emergency situations and have strong protective effects; and for those who are keen on self-defense skills learning, they may be more inclined to choose some small styles that are convenient for practicing control flexibility as auxiliary props; of course, many people include shields in the collection list simply because they appreciate the strong historical and cultural atmosphere contained in the shield.

Mr Wang, a frontline police worker, shared his personal experience: "Once we encountered intensive bombing by flying objects of unknown origin in the process of dealing with a mass incident, the situation was very critical, but fortunately everyone was equipped with a new type of fully enclosed anti-riot shield, which successfully defused the danger without causing any casualties." This undoubtedly confirms the fact that a good quality shield plays an irreplaceable role at a critical moment.

In addition, the shield also carries a profound spiritual implication. Whether in the sports arena, athletes hold up a huge trophy-like shield souvenir symbolizing victory and glory to celebrate the moment of achievement, or the heroic characters in movies and TV works hold up the shining light shield to face up to difficulties and fight against evil forces, each fragment can touch the heart's deep resonance of the belief in bravery and fearlessness, thus inspiring more ordinary people to face challenges bravely in real life, establish firm confidence and keep moving forward.