Difference in Nike VRS and VRS X?

Looked at these the other day,  and also the Covert 2.0   What does the X mean in the VRS X?  Is it more of a GI club,  or does it have something to do with the shaft?  Or none of these?  Just got me wondering,  and I can't find anything about it.

No?  I just thought maybe the X club was more of a "game improvement" club.  Not sure.

The VRS X is a legacy iron. It is based off the VRS iron, and comes only with a Uniflex shaft (between R and S in flex). Dick's sells it for $299. The research & development costs have largely been recovered from the original VRS, so Nike can sell it for a lower price.

TM's legacy iron is the Burner 2.0, reissued and sold also for $299. It comes with the Burner 85-gram shaft, with an R or S flex.

The clubmakers offer the legacy irons as an entry-level set for new golfers, or proven technology for established golfers on a budget.

Many Big Box Stores like Dicks Sporting Goods sell discount versions of big name clubs by substituting with inexpensive/discount shafts, etc, etc, etc......  I wouldn't be surprised if the clubhead is modified too.

There is nothing wrong with this because you get what you pay for.  Whether your budget is $300 or $900 for a set of irons..........the point being,  there is club for every budget.  ....now go get some clubs and tee it up!!

My nike vrs irons do not have nexcore inscribed on the clubface. I'm assuming these are the vrs x model. Does this mean these clubheads are made of cheaper materials, and do they not really have nexcore technology?