Sake is sold in volume units divisible by (one "gō"), the traditional Japanese unit for cup size. Sake is traditionally sold by the gō-sized cup, or in a (one "shō" or ten "gō") sized flask (called an "isshōbin", or "one shō-measure bottle"). Today sake is also often sold in bottles, which are divisible into four gō. Note that this is almost the same as the standard for wine bottles, which is divisible into 4 quarter bottles (187ml). Particularly in convenience stores, sake (generally of cheap quaity) may be sold in a small bottle or a single serving (one gō) glass with a pull-off top ( "kappu-zake").