This went in my Glock 17, which is going to be my dedicated competition gun for USPSA Production division next season. The Vanek Classic Trigger Kit (www.vanekcustom.com) is Charlie's Production legal drop-in kit. Comes with: -Modified 3.5 lb Connector -Modified Trigger Bar -Modified Firing Pin Safety Plunger -Modified Spring Cups -Trigger Housing with Over-Travel Stop (preset) -Springs Old(top) vs New(bottom). Can you tell he's done some polishing? Old(right) vs New(left) Firing Pin Safety Plunger. Polished, looks like some material taken off the top of the plunger, and a much lighter spring Old(right) vs New(left) Spring Cups. Hard to tell from the pic but the modified cups have channels cut in the rim, similar to the OEM marine spring cups. These are a bastard to install unless you have tiny fingers. While I was at it I also assembled and installed a Wolff non-captive steel guide rod & Wolff 14lb recoil spring. Results... drastically smoother pull with a much crisper break and no overtravel to speak of. I stuck with the OEM weight striker spring to make sure it will reliably pop WWB primers, so while the pull is noticeably lighter it is not as light as it could be. If I ever start hand-loading 9mm I'll swap in the lighter striker spring.