I got mine from speedshooter.c o m. They work good but makes it a little tricky to install the firing pin without the plunger to hold it in place while you slip in the firing pin stop, mine are sigs with the external extractor so it is tricky to hold the firing pin inside with a punch, try to align the plug (dummy extractor head) and slide the stop in. Don't take it apart at the range unless you have a spring type extractor or there is a good chance you will say bon voyage to your firing pin and spring lol