Midori/Travelers company passport size notebook. It’s a modular system that can hold up to 3 inserts comfortably at a time and the inserts come in different formats from blank pages to year calendars
Midori Traveler's Notebook Journal Passport Size - Brown https://www.amazon.com/dp/B003SNV0YQ
Midori made something called the traveler's notebook. I've thought about buying one of those as it's a cute little system they've built. It's almost like a wallet that stores a notebook within it, so it's something that I could keep in my back pocket when I need to jot a note down.
Here's a link for it, tho it's a bit pricey.
https://www.amazon.com/gp/product/B003SNV0YQ/ref=s9_dcacsd_dcoop_bw_c_x_4_w
Just about all my pens and ink combinations show through on the Midori paper, but it is a rare ink that will bleed through or feather. My favorite combination for my Midori Passport is my TWSBI Diamond 580 medium nib with Sailor Yama-Dori ink and this clip. The ink shades and sheens on the paper, doesn't show through as much as many other inks, and has a faster dry time than most also. A fine or extra fine nib would show through even less, but I don't like those tiny nibs for my monster handwriting.
It's a Midori Traveler's Notebook Passport size notebook. Midori Traveler's Notebook
I think the guy was using some sort of TWSBI fountain pen, best guess TWSBI Vac Mini
You can make your own, google make your own Fauxdori (what they call a fake Midori) This guy has all sorts of goodies for it
Honestly, I think the Midori came with the red blank page insert, but I can't recall...
Anyway, it's bad ass. They have a larger sized Midori but it's much larger than wallet sized and not my thing.