This is a Rear Fully Adjustable sight, Black Serrated, for the Ruger pistol, model Mark II. This sight uses the original Ruger stock front sight and sits low profile when mounted. Additional wrenches are included in the package. These are LPA brand sights that come from Italy, they are top quality. The rear sight is fully adjustable, for elevation and windage, so you may adjust it in any way for your liking to correct your pistols point of impact. The sight set is made of steel constru ction, Not plastic. These sights use the original dovetails/slots on the pistol slide. These are the best sights on the market today to improve your pistols sighting. LPA Part Number TPU22RG07.