The Ruger SP-101 has never had fully adjustable rear sights on any model. Only the .22, and .32 had windage adjustable rear sights. I sure wish they did offer them! The earliest ones were .38 Special only, and then they came out with a .357 (125 grain bullets only) and then they lengthened the cylinder and offered it in .357 all bullet weights. All .38's, and,357's so far have been fixed rear sight models.