The Action Army Piano Wire AEG Spring M120 delivers consistent performance and reliability for airsoft AEG rifles. Engineered with high-quality piano wire construction, this spring maintains its tension and durability through extended use, ensuring predictable chronograph readings and stable fps output. The M120 rating provides a moderate power level suitable for recreational play and skirmish environments. Piano wire springs resist fatigue and deformation better than standard alternatives, making this an ideal upgrade or replacement for players seeking improved longevity and performance stability. Compatible with standard AEG gearboxes. Recommended for users looking to maintain or slightly increase their rifle's velocity while preserving reliability and shot consistency.