Positive-pressure air respirator www.dehsm.com/category-46.html系列产品配有视野广阔, bright, airtight good full face mask, air supply device with a smaller volume, light weight, stable performance of the new air supply valve; the selection of high-strength back plate and a higher safety factor of high-quality high-pressure cylinders; decompression valve device is equipped with a residual gas alarm in the prescribed cylinder pressure range, the pressure of the gas cylinder. The decompression valve device is equipped with a residual gas alarm, which can send an audible signal to the wearer to remind the user to evacuate the scene in time within the prescribed cylinder pressure range.