Spring Guide for Next Gen M4/416 series

Ergal spring guide for new generation
MARUI M4/416 SRE gear box (GM4S).

The shape of the rod makes it compatible with most of the springs on the market today.
The piece is in ergal anodized for 40 hard to ensure high performance and long life.
This spring guide increases the ball speed by 2/3 meters per second.
100procent MADE IN ITALY