I purchased the front sight only at first, .195/.125 and in combination with the stock rear sight is very fast to acquire the target. Unfortunately there is way too much space in the rear for an accurate shot because the rear notch is too large, approx .140. This new rear sight addition makes all the difference in the world. Note: it was tight at first to install so I filed it down to fit and I almost filled too much. It is not as snug as I would like but it has a set screw along with some loctite should do the trick keeping it secure. Save yourself some trouble and Just but the set. Great product.