AI:The product is a Warhammer 40k LEVIATHAN RULEBOOK, which is a core rules book for the Warhammer 40K game. It is in English and is produced by Games Workshop. This hardback rulebook is essential for players of Warhammer 40K looking to understand the game mechanics and rules in detail. With the 10th edition being released, this rulebook serves as a valuable resource for players looking to enhance their gameplay experience.