Galactic standard weight was a standard unit of measurement.
In 2270, James T. Kirk offered an Orion captain the dilithium shipment carried by the USS Huron as well as an additional galactic standard weight container of dilithium in exchange for the strobolin that the Huron was bringing them, as they desperately needed it to cure Spock's choriocytosis. (TAS: "The Pirates of Orion")