This genuine Glock factory fixed rear sight is a 6.9mm polymer unit with a white U-outline notch. It drops into the standard Glock dovetail for a factory replacement. Features: Genuine Glock OEM polymer rear sight 6.9mm sight height White U-outline notch Standard Glock dovetail fit This wide-body 6.9mm profile fits standard-frame Glock models and does not fit the slimline Glock 42, 43, 43X, or 48, where it overhangs. Match the sight height to your front sight for a correct point of impact. GLOCK is a registered trademark of GLOCK Inc. 3CR Tactical is not affiliated with, endorsed by, or sponsored by GLOCK Inc. Any reference to GLOCK products is for identification and compatibility purposes only.