In 293, Diocletion introduced a new denomination to replace the antoninianus (or aurelianianus) with a laureate portrait, a copper core, and a 5% silver plate, c. 28 - 32 mm diameter, on a consistent weight standard of 10.75 grams. Diocletian's denomination is commonly called a follis (plural: folles) but according to Kenneth Harl, the type should be called a nummus (plural: nummi). The follis was initially tariffed at 5 denarii communes, but was later devalued to 12.5 d.c. and then to 25 d.c. Smaller fraction were struck with a radiate portrait, called "post-reform radiates." The large folles of the Tetrachy did not circulate after 306 when they were replaced by smaller coins.  

In 293, Diocletion introduced a new denomination to replace the antoninianus (or aurelianianus) with a laureate portrait, a copper core, and a 5% silver plate, c. 28 - 32 mm diameter, on a consistent weight standard of 10.75 grams. Diocletian's denomination is commonly called a follis (plural: folles) but according to Kenneth Harl, the type should be called a nummus (plural: nummi). The follis was initially tariffed at 5 denarii communes, but was later devalued to 12.5 d.c. and then to 25 d.c. Smaller fraction were struck with a radiate portrait, called "post-reform radiates." The large folles of the Tetrachy did not circulate after 306 when they were replaced by smaller coins.