Promag Fn Five-Seven 10/30 Magblock (5.7mm)

This Magblock fits the Promag FN 5.7mm 30 round magazines and will limit them to 10 rounds.  Easily installed in seconds at the base of the spring. It is held in place with spring tension alone or can be glued or epoxied if desired.

-Simple install to make Promag 10/30 FN 5.7 Magazines.

-No modification to the magazine is required.

-Lightweight and will not interfere with magazine reliability.