I placed an order with Sofirn and included a pair of 21700 spare 5000mah batteries for my new lantern. See my order screenshot.
What they sent were two 21700 5000mah batteries, but they were nicely tucked inside a pair of SM11 zoomable lights. From what I’ve been able to gather from reading the reviews here https://www.sofirnlight.com/products/2-21700-5000mah-flat-top-and-button-top-batteries?cfb=7574f7dc-f055-4c7f-926b-51b11623da6b&ifb=7574f7dc-f055-4c7f-926b-51b11623da6b&scm=search.v39.101.102.103.104&score=1&ssp=&spm=..search.search_1.1 this is a common practice, apparently in order to meet some sort of customs requirement.
FYI
by Kygunzz