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. The added weight helps the magazine drop free easily for faster reloads. CNC machined from billet aluminum. Hard Anodized. Made in the USA. Mfg: Taran Tactical Innovations