HYZ4 positive pressure oxygen respirator was developed and produced by scientific researchers from many domestic mining safety equipment companies based on the physiological conditions of Chinese mine rescue team members and the geological conditions of mine production. It is suitable for coal mines and mines. Long-lasting work-resistant personal protective equipment for disaster relief environments. This product adopts the US NIOSH technical specifications and the EU EN145 product standard equivalently, and has obtained a number of technical and appearance patent technologies.