Byzantine coin 1 [решено]

Please help me identify this. 

1.93 grams, 16 mm, bronze?

Bought as Byzantine tetarteron of Manuel I 

Yes, Sear 1978.

Some places refer to this as a ½ tetarteron (Wildwinds, and here: https://www.acsearch.info/search.html?id=10119214)

Others refer to it as a tetarteron: https://www.acsearch.info/search.html?id=10658289 ;

Thank you!