This helmet has the stem of the regulating escape valve extended into the inside of the helmet, with a large button on same, so that this valve may be opened by a thrust of the diver's head against it, allowing the air to ecape quickly from the helmet.
This style helmet comes with a screw type front window, vertical oval side windows and a hand machined exhaust. The breast plate comes as the commercial style with 2 thumb screw loops for air and safety line as well as 2 lashing posts which are press fitted from the inside of the breast plate, a very nice hand worked feature.