Nichia 144AR vs 144ART – what’s the difference?

A year ago I ordered a Skilhunt H300 headlamp, and the label on the box said Nichia 144AR. Recently I ordered a H300 for my dad from the same store and the box says Nichia 144ART, even though the store lists it as 144AR.

What does the T mean? I haven’t been able to locate any information about it.

Picture of the box labels:
https://imgur.com/a/pxDoi4U

by dave3432042