Features SiCr spring steel construction Color coded ends make power identification easy Closed ends reduce bending Power ratings were attained using a 300mm-length 6.03mm-diameter inner barrel with a volume-matched cylinder and no hop-up applied. Choice of parts used will affect the final muzzle velocity Ultimate Mil-Spec AEG springs are manufactured out of the best steel (SiCr) available for springs. With a minimum loss in power and consistency, the Mil-Spec spring series is the ULTIMATE choice for your AEG. The Mil-Spec springs are color coded for better identifying them when switching out the spring for different skirmishes. The springs are designed from the start to deliver the best output while keeping it's coil strength, consistancy, and quality. With the closed and ground ends, the spring remains in place during use to prevent a reduction in ROF due to bending. Power: M95 290-350FPS Compatibility: Most popular Airsoft AEGs Material: Spring Steel Manufacturer: ASG