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!
A4/A3/A2 Funko Pop SUPER SIZE Box Digital Template for 6/15cm Figure - Etsy
Buy Pop! Owl as Prince at Funko.
Amazon.com: [6 Pack] 6-Inch Funko Pop! Protector Clear Display Case Box for 6" Funko Pop! Figures - 0.50mm PET Plastic : Toys & Games
NEW SIZE* 8pk Box Size Funko POP! Box Protector 0.50mm thick PET Plastic Disney | eBay
NEW UV & SCRATCH RESISTANT Funko POP! Moment Size 0.50mm Protector - 1 – Kollector Protector
these two pops are the same size even though one comes in a 4” box and the other in a 6” : r/funkopop
Custom A4 Pop Box for your Custom Funk Pop | Pop Vinyl FAQ
Plastic Box Protector Cases for Funko Pop! 10" Inch Vinyl .50mm Thick - Walmart.com
Collection Storage Protective Box | Funko Pop Box Size Inches - 4inch High Quality - Aliexpress
A4/A3/A2 Custom Digital Funko Pop Box Designing Service - Etsy
Amazon.com: MALKO 10 Inch Funko Pop Protector | Compatible with All Vertical 10" Vinyl Figures Newer & Old | 2 Pack : Toys & Games
Funko Pops! - The Sizes, Terms, and Variants
Understanding Funko Pop Sizes [The Collector's Guide] – ToyShnip
A4/A3/A2 Funko Pop Box Digital Template for Standard 4 / 10cm Figure - Etsy
Plastic Box Protector Cases for Funko Pop! 6" Inch Vinyl Clear .50mm Thick - Walmart.com
Understanding Funko Pop Sizes [The Collector's Guide] – ToyShnip
Funko Pops! - The Sizes, Terms, and Variants
Amazon.com: MALKO 6 Inch Funko Pop Protector Compatible with Funko Pop! 6" Figures | Sturdy 0.5 MM Thick Recyclable Plastic | 6 Pack : Toys & Games
Funko Pops! - The Sizes, Terms, and Variants
100 Pack] Diamond Guard Premium Pop Protectors for 4” Funko Pop!
Evoretro Funko Pop 4 Inch Protective Case | Maine Vintage Toys
Amazon.com: EVORETRO Funko Pop Protector - 20-Pack | Funko Pop Display Case - Compatible with All Standard 4 Inches Funko Pop Figure, 0.35 mm Thick PET, Anti-Scratch, Stackable, Will Last for Years