On the package it is written "3000 PSI MAX". So it is at least a 3.0. Just the fact it is good up to 3000 PSI means that if your PW is something like 1800-2000 PSI then you will definitely be losing more PSI when using those nozzles compared to using the same size nozzles that came with your PW.
One of the things I paid a lot of attention when I bought my electric 2000 PSI PW was what nozzles came with it? And then how long the hose?
P.S. Someone in here should grab a screwdriver and open the PW and take a pic of the label on the pump and post it here. This should be done with both the Kobalt and the Ryobi. I did that with one of my PWs and posted the pic here. It seems the last two numbers on the first line might correspond to the actual PSI of the pump. Not 100% sure yet.