This one kilo bricks are made of excellent ancient trees form Lincang, Yunnan. They were tightly pressed and stored in Taiwan for 15 years in very dry storage almost reminds me of teas stored in Europe. (nor really that dry)
Taste is still slightly bitter,  in later infusions bitterness fades away and old trees quality and energy prevails. 
Please try sample before buying whole cake to be sure you like it!