| Platform | Mk57 |
| Caliber | 5.7x28mm |
State/local magazine capacity restrictions may apply. Customers must review Magazine Shipping Policy prior to ordering.
10rd Magazine Extension Kit, 5.7x28mm
Increase the capacity of your 5.7x28mm magazines by 10 rounds. This magazine extension kit is only designed to work with Gen 1 FN®* Five-seveN®* magazines.
