Pulmosan AL 170 Air Line Mask

The Pulmosan AL 170 Air Line Mask was made of light gray rubber with two large round eyepieces. It had a button exhale valve on the left cheek, and a thin braided hose that was connected to a supplied air system. Made by Pulmosan Safety Equipment Corp.
Similar masks in my collection: Pulmosan 1750 Junior, LECCO No. 45