US c.1920's-30's MSA Industrial Braddock Amonia Mine Safety Mask

A rare mine working piece of safety and escape apparatus. With its style evident on the US WW1 Military Box Respirator. This is well preserved example. Black rubber face mask with all its intact rubber head strap, glass eye pieces and ribbed rubber breathing tube attached to a box filter with canvas carry bag and waist ties. Near unused condition. Comes with its painted fibre hard shell storage box. The interior fitted and the inside lid with instruction label. Both mask and storage box in very good condition and seldomly seen.