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The follis (Latin follis - plural folles) it was a great bronze coin introduced around in 294 with the monetary reform of Diocleziano. It weighed around 10 grams and it contained ca. 4% of silver, for the more in the thin superficial layer. The word follis points out a pouch and there is an evidence that this term in the antiquity was used for pointing out a pouch sealed container a quantity fixed of money.
The follis of Diocleziano, despite the efforts to freeze the prices through the edict on the maximum prices imposed in 301, you/he/she was revalued and meeting place. To the time of Costantino I, the follis was smaller and to bad punishment it contained some silver. A bronzes series Costantiniani was introduced in halves the IV century, even if the specific denominations are not clear and discussed from historical and numismatic. The follis was reintrodotto as a great bronze coin (40 nummis) in 498, with the monetary reform of Anastasio, that included a series of bronze denominations with their value marked through the Greek numbers.
The Nummus Centenionale (lat. Centenionalis) and the Pecunia Maiorina (Maiorina) were coins in bronze introduced in 346 with the monetary reform of Constant and Costanzo II because of the strong devaluation of the follis. Their value is not sure, but from the name of the centenionale you/he/she can be thought to a cent of siliqua or miliarense
The fals (corruption of follis) it was a bronze coin sent forth by the califfatis Omayyade and Abbaside beginning from the end of the VII century, initially as imitations of the Byzantine follises.