Units
1 jin 斤 (in mainland China) = 500g
1 jin 斤 (in Taiwan) = 600g = 16 liang (两) - Taiwanese tea is typically sold in 4 liang or 150g packages.
Semantics
Black tea refers to teas that have undergone further fermentation after steaming. Hunan, Sichuan, Anhui, and Guangxi provinces are the original producers. Puer technically falls under this category; raw puer undergoes the post-fermentation at a slow pace with just time egging it on, whereas with ripe puer, people intentionally hasten the process vis-a-vis increasing temperature and moisture of sundried tea in a contained environment.
Red tea refers to teas that go straight from wilting and rolling to fermentation and are then dried and often baked to heighten fragrance
This is a gaiwan