Promo board and one dry erase marker that mixes the blue and red editions.
Can be used for a 7th player, or for a 13th player when combining the red and blue edition.

Was handed out at Essen Spiel 2018 when buying both the Deep Blue and Blazing Red editions.

For more information, please refer to the BGG listing (called Railroad Ink: Promo Board #1 - Blue Train on BGG)