... tightness good properties. Cylinders work pressure,30Mpa .back frame for high strength of nonmetal materials, level pressure ... , pressure reducer,warning whistle,pressure gauge,back plate and carbon fiber cylinder. Wearing quality 10.2kg.Mask(ISI):Conform ... The alarm whistle loud.Backboard uses high strength nylon carbon fiber compositematerials, high strength ,resistant to collision, changeful form ...