Found a source for listening tube rubber. Pics added

[startgroove]

"I.D. 6mm; O.D. 9mm. Rubber thickness 1.5mm." Thank you for those dims. Russie

[edisonclassm]

Listening tube rubber should be a little on the rigid side in order to transmit the sound optimally. "Squishy" tubing tends to thwart the sound transmission. Years ago I found a roll of fairly rigid plain white rubber tubing, without the ridges, of the proper size from a business here in Buffalo. Unfortunately they are no longer around. I since found a scientific supply that had the red rubber that worked extremely well but like Shawn said, they no longer supply it. below is a link I found online. Looks like the more ridged red style that I bought from the Scientific supply house years ago. Give it a try.
https://www.schoolspecialty.com/frey-sc ... GAQAvD_BwE

[colmike1]

I did recently find some pure, machine made, white tubing in China through Aliexpress. It is the best "authentic" looking pure rubber tubing that I have found. https://www.aliexpress.com/item/3233404 ... 3.2.ZaE1YM

Its $27.00 for 5 Meters or about $1.65 a foot with free shipping. It takes a few weeks to get here.

I decided to give this a try. Will post pictures when it arrives. Thank you all for your input.

[colmike1]

I did recently find some pure, machine made, white tubing in China through Aliexpress. It is the best "authentic" looking pure rubber tubing that I have found. https://www.aliexpress.com/item/3233404 ... 3.2.ZaE1YM

Its $27.00 for 5 Meters or about $1.65 a foot with free shipping. It takes a few weeks to get here.

I decided to give this a try. Will post pictures when it arrives.
Thank you all for your input.

It has arrived and I am very pleased with it. It is a hair larger on the OD, but I was able to make it fit. I have over 4 meters left, so if anyone is needing some, please let me know. Thanks again for the suggestion.
Mike