Sia Tong Mango is a Thai variety mango, one of the many Nam Doc Mai versions.
 
Taste: The flesh is yellow, silky smooth and has a floral flavor with honey sweetness lacking any tartness or acid component. Fiberless.
Fruit size: Medium (0.75 - 1.5 lb)
Tree size: Medium (15 - 20 ft tall)
Season: June - July
Thai variety