RSNV image intensifier tube (IIT) is an electro-optical device that converts faint light into electrons via a photocathode, accelerates and multiplies them through high voltage, then strikes a phosphor screen to produce enhanced visible images. Its core components (photocathode, microchannel plate/MCP, and phosphor screen) enable night vision under extreme low-light (e.g., starlight), widely used in security, and scientific applications.