I installed my new GL2006 Hi-Viz sight last night. It took a bit longer than the 20 mins. other posters have claimed. I spent a bit of time touching it up with a Birchwood Casey Black touch up pen, to blacken a couple of scratches from the filing, and it takes a few mins to dry before handling. No use posting photos, as it looks just like the rest of the sight mods. It's been raining for a couple of days, so I haven't been able to test it out yet. I printed out a few targets that I down loaded off line, free. I will get a better idea of POI that I wouldn't get with our steel disk, knock down targets that we normally use for plinking. I did use some loctite blue on the threads but it seemed real thin for some reason. I haven't used the stuff in several years, but I don't remember it being this thin and runny. I did shake the little tube for a couple of mins before using, and it was a brand new tube. Hopefully it will set up nicely. The sight glows very well, even in low light conditions. I am surprised that Hi-Viz doesn't make a sight specifically for the Sigma. I noticed that it is very popular on the Internet as a common sight replacement choice for Sigmas. I will post my test results as soon as I get a little dry weather. My son-in-law is interested in replacing his Glock sight, now that he has seen my mod.