Need some help rigging up gas mask tubing

HI all

I want to make a complex tube assembly for a costume with a israeli gas mask. The mask filter thread is a standard 40mm, and so I want to use the standard metal connector from these tubes:



But I want to use a different tube - like those for washing machines. I think they come in 25mm, 32mm and 40mm diameters. Not sure if this is inner or outer diameter.

Does anyone know what is the diameter of the metal tube connector (the part that is hidden inside the tube above?)

so I can find out what tube diameter I need to fit onto these metal connectors.

Just from looking at the reference photos online, I would think that was 1.5 inch (40mm) hose and the inner diameter should be ok to go over the fitting and with a crimp hose clamp you would get what you were looking for.
Something like this:
http://www.ebay.com/itm/New-Army-Ga...hash=item361c43f26e:m:mcCQtK7O6ODZit6jB5qlCHQ

I have both the fabric and the rubber versions of the gas mask hose. I took the measurements of the fabric one:

Coupling with thread on the outside:

- Inner diameter of the coupling: 1" (25mm)
- Outer diameter of the fabric hose at the attachment point to the coupling: 1.25" (30.5mm)

Coupling with thread on the inside:
- Inner diameter of the coupling: 15/16" (24mm)
- Outer diameter of the fabric hose at the attachment point to the coupling: 1.25" (30.5mm)

This hose feels like there is rubber underneath the fabric so based on the measurements I think that a hose with an ID of 1" should fit over the coupling.