This is a 540 cube of cards that are (or will be, as of Jumpstart) legal on MTG Arena. This cube is meant for players who want to play Draft games on Arena but without necessarily playing the official Arena cube, or when the official Arena cube isn't active.

Players can use the online utility https://dr4ft.info/ and the ID arena_mod to draft the cubes and then do deck construction and play using the Friend features of MTG Arena.

Note: This does require players to have reasonably deep MTG Arena collections, or a willingness to burn Arena wild-cards to complete decks.