As usual, the press omits the technical specification of the radiation source, leaving one trying to deduce it from the roundabout descriptions in the article. Would it kill them to put something like "a 37 MBq Cs-137 source" somewhere? Granted, the WA Health press release is not too informative either, but at least it identifies the material.
(The X8 capsule from [1] is a dead ringer for the one described.)
[1] https://www.qsa-global.com/industrial-cs-137-gamma-sources
I expect nobody outside of the technician who ordered the shipment to understand any of those words.