What is iron banner shaders?

Iron Banner shaders are cosmetic items in the game Destiny 2 that can be used to change the appearance of a player's armor and weapons. These shaders are earned through participating in the Iron Banner mode, which is a competitive PvP (Player vs Player) event that occurs periodically throughout the game's seasons. Iron Banner shaders are often designed to have a metallic, industrial look that fits with the theme of the Iron Banner event. Players can apply Iron Banner shaders to individual pieces of armor or weapons, or to all of their equipped items at once using a shader application tool called the Shader Preview.