I just ordered a 10# box of these from a grower in Florida:
These are brahm kai meu mangoes (that's the Vietnamese name, it has a different name in Thai). The grower picks them green (I can't wait to make a green mango salad... I miss them!!! It will also be good with a salty/sweet/chili dip) but if I let them sit, they will ripen. If it is close to what I've had in Vietnam and Thailand, I will be one happy guy.