I'll guess too
, Antique Fire Fighter's Air Bellows for Helmets - Leather mask is attached to a hose, which is attached to bellows. The firefighter would don the leather mask, while a second firefighter would provide air by operating the ...bellows. Signals were given by tugs on the hose by the wearer, 1 tug meant more air, 2 tugs less air, 3 tugs help me out.