Tagkat, I ordered those "Loading Key & Keycaps from the online site directly and they work great. First you have to realize it's an "Assist" tool, not a speedloader. It simply makes it easier for you to load the magazine because you have more metal to grab onto. When you put the new button in the mag, it has hole through the button so you can put the "key" and the"cap" through it and you pull the spring down with very little effort. From the conversation I'm hearing some people think you pull the button all the way down and drop the bullets into the mag. That's what you DON'T t do. You simply load it the normal way by just pulling down on the spring so you load one bullet at time with much less stress on your fingers. I also found it easier with the new button in the mags to load without using the key & cap then before with the stock S&W mag button. I bought enough for all mags and some extra for further purchases. I'm not plugging the company, I'm just saying it's an easier way to load your mags. and the price to me is well worth it