This is just a simple tray helper for playing the Japanese Riichi variant of Mahjong. It holds the dice during game, as well as offering a tray to roll the dice in.

There's indicators on each side for seat wind, as well as a slot to hold a token indicating prevalent wind. Simply rotate the tray whenever seat wind changes, and swap the prevalent wind token around to keep track of the player who started as east.

Another feature is a small slot to hold riichi bets.

The tray is designed to be the correct width to help with lining up discarded tiles.