I just realized that the new Funko 3-packs have the same dimensions as two regular Pop boxes side-by-side, meaning you can slip two Pops into a 3-pack protector and they'll fit perfectly!
these two pops are the same size even though one comes in a 4” box and the other in a 6” : r/funkopop
Funko POP! Movie Moments Box Protectors made with 0.50mm thick PET Aci – Kollector Protector
Amazon.com: EVORETRO Pop Protector - 20-Pack - Compatible with All Standard 4 Inches Funko Pop Figure, 0.35 mm Thick, Stackable PET Plastic Funko Pop Display Case : Toys & Games
10 Inch (WIDE SIZE) Funko POP! Box Protector made with 0.50mm thick PE – Kollector Protector
Was asked by another redditor to show a comparison of box sizes between a Youtooz and a POP. The only difference is the POP is just a little taller but all other
How much do Funko Pops weigh? Funko Pop Dimensions & Sizes
Custom Box Template for A4Size Printers | Pop Vinyl FAQ