The most notable jade products of these regions were the vast amounts of penannular and double-headed earrings and pendants known as "lingling-o", primarily produced in the Philippines and the Sa Huỳnh culture of Vietnam, though remarkably mostly with the raw jade material sourced from eastern Taiwan. These typically depict two-headed animals or were ring-shaped with side projections. They were indicative of a very active ancient maritime trading region that imported and exported raw jade and finished jade ornaments known as the Sa Huynh-Kalanay Interaction Sphere. They were produced during a period between 500 BCE to as late as 1000 CE, although later examples were replaced with metal, wood, bone, clay, green mica, black nephrite, or shell materials, rather than green jade.