Pokemon 4-Pocket Portfolio: Sword & Shield SWSH4 - Rules of Play says:

We know you Gotta Catch 'em All, so keep your valuable cards safe and organized with Ultra PRO's 4-Pocket Portfolio. Made in California, USA. Trading Card Game, these portfolios are ideal for sorting, organizing and storing trading cards. Holds 40 collectible cards single-loaded or 80 double-loaded. Each Portfolio includes 10 high-clarity, archival-safe pages (each hold up to 8 standard trading cards), plus 2 additional pages to hold Oversized cards.