Modifying a gun requires research and decisions.  One of the most common changes for the Glock is the slide lock.  Glock does not call it a slide release, because the design team assumed that you would pull back the slide to  release it.  Thus, the slide lock is very small because it was intended to stay out of the way.  The modern technique of shooting drives many shooters to put in and extended slide stop.  In this video, Ferrari Steve discusses installing the Glock OEM extended slide stop, which comes standard on the Glock 17L and Glock 35.  It can be easily added to any Glock pistol to aid in your slide stop operation.

IMPORTANT: 2 pin models require a different slide stop than 3 pin models, so be sure to order the correct one for your application.