Perfect "Top Half" for a D.I.Y. Custom Pistol The Brownells Iron Sight Slide for Glock 20A(R) Gen3 enables you to build a custom GlockA(R)-style pistol with a slide that sports distinctive front and rear cocking serrations. The front serrations aid in manipulating the slide, especially for quick chamber checks. Both the front and rear serrations are cut to the same depth as the GlockA(R) factory slide serrations to ensure preservation of structural rigidity. The top edges and the front around the muzzle area are chamfered to reduce the risk of snagging on clothing and to make holstering the pistol easier. Accepts Gen3 GlockA(R) 20 internal parts Factory Mfg: Brownells