3M 7000128239 Half Facepiece Reusable Mask is designed for welding protection against mold and silica hazards. It is compatible with 3M PAPR Systems and offers enhanced comfort with a silicone faceseal and cool flow exhalation valve. The mask provides gas and vapor protection against hydrogen fluoride, mercury vapor, chlorine, organic vapor, acid gas, ammonia, methylamine, and formaldehyde. Its drop-down feature and bayonet connection type make it convenient to use. The mask weighs 0.37 lb and is made of silicone and nylon for enhanced durability. It comes in medium size with a 4-point quick latch harness for optimal fit. Spare parts are available, while clip-on welding shield and eye protection are not included.