Convert from flask to kwan [Japan]

Unit Definition (flask)
The flask is a commercial unit of weight formerly used to measure liquid mercury (or quicksilver, as it was called). The flask was equal to 76.5 pounds avoirdupois, which is equivalent to almost exactly 34.7 kilograms.

Unit Definition (kwan [Japan])
The kwan is a traditional Japanese unit of weight equal to 6.25 kin, which is about 8.27 pounds or 3.75 kilograms.