Coaxial pipes for level sensors are not a specific brand but a product category used in industrial level measurement systems. These components are typically offered by various manufacturers specializing in process control and instrumentation. For instance, companies like Siemens (Germany), Emerson (USA), and Endress+Hauser (Switzerland) produce coaxial probe level sensors for industries such as chemical, water treatment, and oil & gas. These sensors utilize coaxial pipes as waveguides for radar or TDR (Time Domain Reflectometry) signals to measure liquid or solid levels in tanks. The coaxial design ensures accurate signal transmission even in harsh environments with temperature variations or vapors.