Quan was a weight used on a balance. The Qin Quan was made of bronze or iron. Inscribed on the body of the Quan is a 40-character imperial edict on the unification of weights and measures issued in the 26th year of the reign of the First Emperor of Qin. There is also an inscription of two characters cut in relief which means "Eight catties". According to the actual measurement, one catty is reckoned to be equivalent to 257.925 grams today.