I recently bought making magic volume 1 and 2 by martin lewis and would love to use the holder instead of the wineglass. I tried building one myself but forgot to cut down the top of the holder to grab the card easily. And I picked out a bulky stem which slowed down the process of the card change ( If you know what I mean)
Is there someone who has this trick and can give me the exact specs so I can build one correctly this time or give me a picture so I can get an idea of how the steam suppose to look like?

I think you can buy a houlette (?) from Martin. Look on his website. It's a great trick and worth a small investment. I know. I use it.

Google Magicraft Or maybe Magickraft