This is a rear fully adjustable sight, white outline, for the Colt Pistol Model 1911-A1 style pistols and clones. This sight sits "Low Profile" and made to work with the original Colt front sight on the pistol. Additional wrenches are included in the package. The dovetail base width is approximately .330" on this series of sights. If this base is wide for your dovetail you will need the 1911 colt Mil spec 70, 80, 90 series version which is a bit smaller at approximately .322". These are top quality LPA brand sights made in Italy. The rear sight is fully adjustable, for elevation and windage, so you may adjust it in any way to your liking to correct your pistols point of impact. The sight set is made of steel construction, 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. Will not work on Novak dovetails. Will not Taurus PT1911 with BO Mar Cut. Will Not fit 1911 Super 38. Will not fit GSG Will not fit Rock Island Armory (Armscor) 1911 A1 Will not work on the Tisaf 1911 from Turkey.