Spring Guide for Next Gen M4/416 series

<p>Ergal spring guide for new generation<br /> MARUI M4/416 SRE gear box (GM4S).<br /> <br /> The shape of the rod makes it compatible with most of the springs on the market today.<br /> The piece is in ergal anodized for 40 hard to ensure high performance and long life.<br /> This spring guide increases the ball speed by 2/3 meters per second.<br /> 100procent MADE IN ITALY</p>