The connector is the angled leaf in the trigger mechanism housing that sets how the trigger breaks. Swapping the standard connector for a 3.5 lb unit, usually alongside a matched spring set, is the cheapest meaningful change you can make to how a Glock trigger feels.
How fitment works
Connectors are generation-specific. Gen 5 revised the trigger mechanism, so Gen 1–4 connectors do not carry over. Spring kits are typically sold as a set — trigger spring, firing pin spring and safety plunger spring — because changing one in isolation shifts the balance the others were designed around.
Fitment chart
Choosing and fitting
Understand what a lighter connector actually does: it reduces pull weight, it does not remove the trigger safety. Anything fitted to a defensive pistol should be function-tested extensively, including a drop-safety check and a full magazine of the ammunition you carry. If you are not confident stripping the trigger housing, have an armourer fit it.