Bought 18800 Meps and front sight was loose. Returned and had set of Meps 18801 sent. Fit great but shoots 4" high at 30' with sight pic 3 and 2" high with sight pic 2. Not happy with this but like the sights. So I stumbled onto XS Big Dot sights and standard dot sights. Like the smaller Standard Dot better since seems more precise. Can anyone tell me what model of standard dot version works on PPQ (part number would be great)? And also how hard to install on my own? Thanks.