This is the Kirkland version of the Costco Friendly Battery Tray. Its designed to hold AA and AAA batteries in sets of 48, which is the amount you will get if you buy Kirkland brand batteries from Costco. This comes in three versions, a 48X48 tray to hold both types of batteries. One 48-battery tray for AA and one for triple AA for printing with smaller printers or for folks that don't use one type of battery or the other.

There is also a Duracell version available of The Costco Friendly Battery Tray at https://makerworld.com/en/models/110429#profileId-118060