The ad recommends that a gunsmith install the sights - good plan. I had to do a lot of filing to get the sights installed. Also, the box says click adjustable for elevation and windage - elevation yes, windage NO. Finally, the rear sight has two small set screws that have to be loosened prior to installation and then reset after the sight is mounted - no tool was provided and no information as to the size, I have a fair number of allen wrenches in both metric and US sizes, but none of them would fit. Other sights I have installed that had set screws came with a wrench.