Not for sale to California residents. A courtesy email will be sent to CA residence who place an order for a base pad that has the capability of taking a magazine past ten rounds. Ultimately a refund will be issued. CA residence can only purchase +0 base pads or GLOCK 43 and GLOCK 42 base pads. The 43 and 42 base pads do not take the mag capacity past ten rounds.∗Remove the metal insert at the bottom before installation∗∗Does not come with an allen key. Because the screws are set with Loc-tite to achieve a nice tension with the pin. If the pin is very loose use a 1/16 allen (hex) to tighten it.∗ ∗ This product will ONLY work on Glock 19 and Glock 23! This product will ONLY work on the Compact 9mm and .40 cal Glock OEM magazines!∗TTI Firepower Base Pad Kit for GLOCK. - The +2/3 and +4/5 does come with a 10% stronger spring. The +0 does not come with or need a stronger spring to operate properly.- Will work on all full size double stacked GLOCKs.- Patented proven push pin design.- Super easy to attach and detach from the magazine.- No specialty tools or devices required to disassemble.- One piece design, no extra parts to possibly lose during disassembly.- Fits the USPSA 140mm gauge.- Works only on high-cap double stacked GLOCK OEM magazines.- Holds extra 3 rounds. - The added weight helps the magazine drop free easily for faster reloads.- CNC machined from billet aluminum.- Hard Anodized.- Made in the USA.- Used and endorsed by World and National Champions Bob Vogel, the GLOCK Shooting Team, Randi Rogers, Allie Barrett, and of course Taran Butler.The Taran Tactical Innovations GLOCK base pad works on GLOCK models 19 /23. This base pad will add 3 extra rounds in 9mm. 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 GLOCK 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 onto the magazine 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.