I just installed this kit on both of my SAR K2-45's this weekend, they say they work on all the SAR hammer fired pistols. I don't have any trigger pull weight devices, but the difference is noticeable! Very pleased. Good $25 investment. I've NEVER dealt with trigger springs before nor am I very mechanically inclined, but the video makes it totally doable. ONE Note: the video says to use a 3/32" roll pin punch for the pin that holds the hammer in place, that did NOT work for me. But, once I switched to the 1/8" roll pin punch, it came out fairly easily.
Just passing this along to anyone interested. And, no I'm not affiliated with them in any way, just a good product from what I've seen so far.