Upgrade your Lancer Tactical Generation 2 M4 rifle with this M120 Metal Spring. This spring replacement provides a FPS of 390 when used in Version 2 gearboxes. The durable stainless steel construction ensures long lasting life and the tough alloy firmly maintains coil tension.

Features:

• Increase velocity up to 390 FPS
• Durable Stainless Steel Construction
• Tough Alloy Firmly Maintains Coil Tension
• Instantly Alter AEG FPS
• Variable Pitch Spring
• Calculated Design for Best Consistency