Magazine extension kit - CMMG, Inc Magazine Extension Kit, Five-seveN Pistol, 10rd

Item would not match up with the magazine that I had. The plastic was slightly off and was leaving indentations in the plastic when trying to get it to lock in place. 4 different people tried and finally stopped before damaging the magazine. Probably would have fit, if shaving some plastic off, but not worth the time and hassel. I do not recommend this product.