Based on polyurethane foam, the MPU series of absorbing materials are usually designed in a pyramid shape, with carbon-based electromagnetic wave absorbers attached inside, and are suitable for microwave anechoic chambers. Considering its excellent flame-retardant performance, the MPU series of absorbing materials are widely used in the batteries of new energy vehicles and the electromagnetic test anechoic chambers of electric vehicles. Generally, the MPU series absorbing materials are painted blue to enhance the overall brightness inside the darkroom, while the tips are usually not painted to ensure high-frequency absorption capacity and minimize damage caused by wear.