What grade is the stone milk tea

According to brand.com, Stone Milk Tea is one of the famous products of Wuyi Rock Tea, which belongs to the middle and high grade. Stone Milk Tea has been cultivated for nearly two hundred years and was famous when Jin merchants traded rock tea. It is a medium-ripe variety and is a famous product of the traditional varieties of Wuyi Rock Tea. The aroma of rock milk tea seems to be sweet like colostrum, similar to the milk secreted in the stone, it is the famous tea in the Song Dynasty Beiyuan Tribute Tea, and the Dragon Tea, Fung Tea, Rock Milk Tea is known as the top quality imperial tea. Therefore, the stone milk tea belongs to the high-grade.