Make sure you order the correct site
First, these are great sights. Very bright and easy to install.
Second, make sure you order the correct model. I did not catch the difference from the Amazon site and ordered the wrong model. Look closely at you sights to see if there is a Ruger logo or not. The Tandemkross site give clear directions for which you need.
As a note on service, when I discovered MY mistake, I emailed Tandemkross and asked what I could do to exchange. I emailed on Saturday and received a reply over the weekend giving me directions. Good luck getting that kind of service from many companies.
Reviewed by: Doug from Utah.