From the short article, it's just a trigger with slightly different geometry that must account for the reduction in trigger pull. There are no springs and this is not the full blown $200+ Apex kit seen in M&Ps... it's a $49.95 trigger (at least the one the OP linked to)...
Apex Now Shipping New Curved Advanced Trigger for Sig Sauer P320 ? Apex Tactical Specialties
I'm certainly game for the next level of trigger beyond my GG PELT... can't wait!When I read the article, it says " soon to be released triggers and kits for the Beretta APX, FN 509, Smith & Wesson M&P M2.0 and Sig Sauer P320. During...
paul / April 25, 2017 / Apex News / 0 Comments"
Then in the separate article below it speaks about the existing triggers
"Apex Tactical Specialties is now shipping the all new Curved Advanced Trigger for the Sig Sauer P320 series of pistols. Designed to reduce trigger pull weight by approximately 2 lbs., the new trigger has an MSRP of $49.95. The new Curved Advanced Trigger is a direct drop-in replacement for the factory trigger and is easily installed without...
paul / April 18, 2017 / Apex News / 0 Comments"
This would leave me and I believe the OP to believe there is yet another trigger they are talking about at the NRA show, that will be different than the current trigger.
Could be just some confusion but the language and the dates of those releases leads me to this conclusion.