Amazon has lots of options here, including some with USB-C. https://www.amazon.com/s?k=usb+hub+grommet&ref=nb_sb_noss_1
That's a search for "USB Hub grommet"
I have charging grommets in my desk surface - 2 USB-A & one AC outlet (no data transmission), but for a hub I have one of these mounted under the desk, which works great: https://www.amazon.com/Headphone-Headset-Hanger-External-Earphone/dp/B07D48GDZ4 (if you're looking for an alternate suggestion). Here's a pic of what it looks like up close/installed.
The way the grommets work is this: You cut the hole and the grommet body fits down inside of it/protrudes from the bottom of the desk surface. The top of the grommet (where the ports are) is just a little bit wider than the hole (so it 'catches') and is raised up a little bit. So they're not perfectly flush, but it's a nice look.
Ended up opting for this:
https://www.amazon.ca/gp/product/B07D48GDZ4/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
Having it hang under the desk is actually a nice space saver. It has an in-built soundcard and aux port for easy and close access. Not to mention, the added usb-ports are a cool extra.
Unfortunately no volume knob. The main reason for wanting a knob was that my keyboard doesn't have one, and it was annoying to have to hold the function (FN) key down to use the multimedia keys located on top (F5 - F11 keys). Although I fixed this by downloading AutoHotKeys and following this tutorial:
https://www.youtube.com/watch?v=GJV1bmxv-1E
The one thing I was unsure about was having a separate external soundcard might get annoying from what I read about on this amazon review:
" You'd expect to listen to music the moment you plug in your earphones, but it turns out that this USB hub actually has a separate sound card, so you will need to go to settings -> change your audio output device, before you can actually start listening to music. So it's not the same as how the internal 3.5mm audio jack works. Even if you unplug your earphones, you'll need to change the audio out again (to internal speakers) before it lets you listen to stuff on your computer. " (https://www.amazon.ca/gp/customer-reviews/R3KSE2EXJM6QH0/ref=cm_cr_dp_d_rvw_ttl?ie=UTF8&ASIN=B07D48GDZ4)
I plan to solve this problem by downloading Soundswitch, and binding F12 to quickly switch between sound output devices:
https://www.howtogeek.com/301290/how-to-switch-windows-sound-outputs-with-a-hotkey/#:~:text=I've%20chosen%20Ctrl%2BAlt,%E2%80%9D%20when%20you're%20done.&text=Now%20whenever%20you%20press%20your,you%20have%20more%20than%20two).
its this one link
Thank you for liking our batttlesations. We appreciate it. ☺️ Here's the amazon link for the headphone hanger. It comes with a usb hub as well. Happy shopping!😅
https://www.amazon.ca/dp/B07D48GDZ4/ref=cm_sw_r_cp_apa_i_x0ihFbZ1C1XD6