1949-50 exhibit-sized card commonly reffered to as "Coca-Cola." These blank-backed cards have no advertising on them whatsoever, so it is unlikely they have any affiliation with the makers of Coca-Cola.
Even so, they are one of the rarer issues of the era and are usually found with players from the Almendares team. The next most common is the Habana team.
Rarer still are cards featuring Cienfuegos players, like this card of Cuban HOFer and Major Leaguer Napoleon Reyes.