In the field of door and window materials, aluminum doors and windows have gradually replaced plastic steel doors and windows, especially in villas, hotels and high-end buildings. Aluminum doors and windows use aluminum extruded profiles as the frame, and the leaf materials are the stressed base materials. They are a kind of aluminum doors and windows aluminum or aluminum plastic composite doors and windows.

One of the most striking aspects of real spears is their diversity. Across different regions and eras, spears have been designed for specific purposes, illustrating how intimately human societies were connected to their environments. In Africa, for instance, the Assegai—a type of spear used by the Zulu people—was known for its long, slender design that allowed for precision in hunting and combat. Meanwhile, the Roman pilum was engineered to be a throwing spear, featuring a unique design that disrupted enemy shields, demonstrating the tactical thinking of ancient Roman armies.