EXACTLY WHAT I NEEDED
As the title states this recoil spring is exactly what I needed for my Frankenstein We have Glock 49 at home build. I needed the recoil spring to use with their guide rod adapter. Worked great and I had zero malfunctions at the range which I'm sure the spring contributed to as a regular glock 17 recoil spring and rod I tired using at first was having many FTE/FTF issues.