This Taran Tactical Innovations Sig MPX Carbine base pad works on the Sig MPX stock 30 round 9mm magazine. This TTI base pad will add 10 extra rounds to your stock Sig MPX Carbine 30 round magazine. This TTI base pad does add a little extra weight to the magazine which helps the empty mag drop free easier for faster reloads. This TTI Sig MPX base pad, just like all of our base pads, is designed to give you the edge over your adversaries. We use our patented push pin design to lock the base pad to the magazine, which makes for easy field stripping and cleaning your magazines between stages. Just push down the pin, slide the base pad on and push the pin up to lock the base pad onto the magazine. Our one piece design is great because there are no extra parts or tools needed to attach the base pad to your magazine. The base pad itself is machined out of billet aluminum and is hard anodized to ensure durable long lasting color. All machining and manufacturing is done in the USA.