The radiate or Post-reform radiate (the actual name, like many Roman coins of this time, is unknown), was introduced by Diocletian

Diocletian

Diocletian |latinized]] upon his accession to Diocletian . c. 22 December 244  – 3 December 311), was a Roman Emperor from 284 to 305....

 during his reforms. It looked very similar to an Antoninianus

Antoninianus

The antoninianus was a coin used during the Roman Empire thought to have been valued at 2 denarii. It was initially silver, but was slowly debased to bronze. The coin was introduced by Caracalla in early 215 and was a silver coin similar to the denarius except that it was slightly larger and...

 even with a radiated crown like Sol Invictus

Sol Invictus

Sol Invictus was the official sun god of the later Roman empire. In 274 Aurelian made it an official cult alongside the traditional Roman cults. Scholars disagree whether the new deity was a refoundation of the ancient Latin cult of Sol, a revival of the cult of Elagabalus or completely new...

, except it misses the XXI that numismatists

Numismatics

Numismatics is the study or collection of currency, including coins, tokens, paper money, and related objects. While numismatists are often characterized as students or collectors of coins, the discipline also includes the broader study of money and other payment media used to resolve debts and the...

 believe was to represent 20 parts bronze

Bronze

Bronze is a metal alloy consisting primarily of copper, usually with tin as the main additive. It is hard and brittle, and it was particularly significant in antiquity, so much so that the Bronze Age was named after the metal...

 to 1 part silver

Silver

Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...

. The radiate had little or no content of silver.
The weight varies between 2.23 and 3.44 grams.

Only one image is defined on coins found Jupiter presents Victory on a globe to Diocletian (Wildwinds) with the mintmark in between the human images