... purge the body clothing equipment, materials and tools on the dust, but also has electronic interlocking functions, and different levels ... vent wind speed 20m / s or more, ensure that the dust effect. 7, on both sides with light, clear instructions working ... velocitymore than 20m/sFilter efficiency≥ 99.99% (sodium flame method) dust particle size ≥ 0.5μmInternal diameter800*900*1950800*900*1950800 ...