Top Hat Tube Dampers?

I have a pair also. I believe Andy said it was plain old Elmer's white wood glue.

Elmer's Glue. Let us know what you think of the Top Hats.

Yes, it is Elmers. Two smallish drops, 45 degrees from indentation and opposite each other. I always let dry overnight before use. I used the Top Hats to wonderful effect in 90's when I had a tube-based preamp, and loved them.

Herbies UlraSonic rx rings are MUCH better better bass,more air etc.

Thanks for the info. I thought it was Elmer's, but didn't want to try until it was confirmed.
I'll let you know what I think about them, after I install them (probably tonight). I'll be using them on a couple of tubes in my phono preamp (Fosgate).

Listened to the Fosgate last night with the Top Hats installed. There was an improvement in the quietness of the background. Music came from a more black background. It was quieter, allowing me to hear deeper into the music. This was not a night-and-day difference with vs. without the top hats, but I do like what they are doing. I'm going to search the internet to see if I can buy another pair from someone, as the instruction manual makes a comment about the effect being cumulative. Thanks again for helping me identify what glue I needed to use.
Happy New Year!