Made in Japan by LayLax, Prometheus Non-Linear Main Springs feature an irregular pitch coils design to reduce mechanical strain on airsoft AEG gearboxes. The non-linear spacing allows for an easier initial compression stroke, easing startup torque on the motor and gears before building full power. Heat-treated for long-term tension retention and stress resistance, these springs feature a specialized, color-coded finish for rapid spring-rate identification. 100% compatible with standard Tokyo Marui AEG gearboxes.