What version of BT does the NB10 (a3260) use?

What version of Bluetooth do the Soundbuds Sport NB10 (a3260) have?

The website and online amazon listing have it at 4.1, but the retail packaging in Walmart has it listed at 4.0.

Been a while since I’ve seen the packaging but from what I could remember the version was not listed on the exterior of mine but the manual and online resources always refer to 4.1 as the revision…