The Prometheus Non-Linear AEG Spring MS90 Violet is a high-quality upgrade for your AEG. Made in Japan, this spring features a non-linear, irregular pitch design that reduces stress on your gearbox, resulting in increased durability and reliability. The special coating also prevents paint flaking, ensuring that your spring will look great for years to come. Additionally, this spring is colored coded for easy identification of spring rates. Upgrade your AEG with confidence with the same great quality as the regular Prometheus Non-Linear springs, now in color. Whether you’re a beginner or a seasoned pro, the Prometheus Non-Linear AEG Spring MS90 Violet is the perfect upgrade for your AEG.