This is 7542 which is known in the world of puer as a definitive recipe. 1975 is the year the recipe was created in 1975. The leaf size is four, with one being the smallest and zero the largest and the factory is two, which is the code for Meng Hai Tea Factory. Da Yi is made by Meng Hai. This batch is 505 so it was the fifth batch of leaves pressed in the this recipe in the year 2005. Typically the first batch is the best, but on this year it was either the fourth or the seventh that was considered the best. This batch of 2005 7542 was wet stored in Hong Kong. This storage technique adds to the darkness and the earthiness. It is also somewhat rare to have Hong Kong stored puer post 2000, but it is always fun to try when it is done well. 

Smooth, fungal, mineral...

Like drinking from a mountain stream, pure and clean. 

Energizing and soothing. 

The weight on this cake averages 331g.