Have you seen these copies of NGC holders before? It seems they're used to hold a collector coin of any date of a certain denomination: https://youtube.com/shorts/xKkdV6sW2x4?si=AUFQnn_pm9Z_han4 In the video description, the person says he's using them as gifts to give away at an upcoming coin club/coin show in the Dongmyo neighborhood of Seoul.
I've been using those types of slabs for years. I like to self slab coins/tokens not worth sending in. And I can put my picture of me in a steam engine
You can buy holders from several Chinese manufacturers that are very similar in appearance with and interlock with NGC and PCGS holders. They aren't sealed, but it's a nice safe storage alternative when you have low-valued coins that aren't worth slabbing comingled with ones that are. PCCB is one, they make just about every hobby accessory you can imagine - stamp and coin. https://www.made-in-china.com/showroom/5d7c3580dfd761d1/
