Interesting Conundrum .......... Kriss Vector Warranty & The M4 Stock Adapter.

If you look at the Kriss Vector Warranty on their website you see the following.

"This KRISS Warranty is applicable to the original or initial purchaser only and it is effective from the date of purchase and lasts for one full year. This warranty can be extended for an additional year on the semi-automatic models (CRB, SBR, SDP) provided the initial purchaser registers the gun on the Warranty Registration page of the KRISS USA website within a 30 day period of the purchase date."

So ...... Two years if you register your Kriss.  You'll also see following in BRIGHT RED LETTERS.

"ANY MODIFICATIONS OR ALTERATIONS TO THE GUN WILL VOID THIS WARRANTY."

Looking under the FAQs I found this regarding SBR conversions of the SDP ..........

 "Removing the butted end piece from the SDP is more complicated than it seems. Please note, any attempts to modify our firearms will result in a voided warranty. As such, we don't recommend individual users attempt to remove the butted end piece themselves as this will void the warranty. There is a charge for this service."

Kriss is now selling the M4 Stock Adapter to individual users.  The installation of which will void the individual user's  warranty.  Interesting.

I find that many warranties aren't worth a damn once you read the fine print.