The post-reform radiate (the Latin name, like many Roman coins of this time, is unknown), was a Roman coin first issued by Diocletian during his currency reforms. The radiate looked very similar to the Antoninianus (pre-reform radiate), with a radiate crown like Sol Invictus. The difference is the absence of the "XXI" that existed on pre-reform radiates, a symbol believed to have indicated a consistence of 20 parts bronze to 1 part silver. The post-reform radiate had little or no silver content. The weight varies between 2.23 and 3.44 grams.
There also exists radiates of Maximian, Constantius I, and Galerius, Diocletian's co-rulers, in the same style.