I went with these to get a more target style sight system on my Springfield TRP non rail. .325" rear height and a .125" notch. The front sight is .140" tall and .115" wide. I can see the windows, but not perfect all the time. I'm scoring 29/30 from 25 yards consistently, but I might go with the .135" notch. Great sight system though.
I recommend investing in a set of calipers so you know what you have currently and help you adjust to perfect. TRPs came with a couple of different sight heights.
My factory sights were .375" rear height and .180" front sight height. (I know now)
The .375" rear is hard to find, that causes you to have to play with the heights. .350" rear and .160" front would have been closer to factory. I bought the .325" based on info in some forums. I did not have calipers to measure and .325" was a known height. I also went with .180" front forge same reason. I was about 5" low at 25 yards. The customer service guys were great, but they have to know what you are looking at to help you better.
They got me where I needed to be with a .140" saving me some money I wanted to change both the front and the rear.
I just have to decide how close I can get these to what I'm getting so easily out of my Glock 17 Dawson sights(Glock sights are a more known quantity). They were very, very easy because the Glock is more consistent with their sights.
No regrets I just want it perfect especially since I hated the factory sights. Once they are on and you are banging that 10 ring you will be glad you did!