Guarder AEG Spring

The SP-150 rating indicates a high-tension spring designed to increase your muzzle velocity significantly. It is intended for builds requiring higher FPS, so ensure your gearbox internals, such as the piston and gears, are upgraded to handle the increased stress.

This spring is specifically engineered for Tokyo Marui spec gearboxes. While it may fit other brands that follow the Tokyo Marui standard, you should verify your gearbox compatibility before installation to avoid fitment issues.

Oil-tempered wire undergoes a specific heat-treatment process that enhances the steel's elasticity and fatigue resistance. This results in a spring that maintains its tension longer and resists deformation better than standard, non-tempered alternatives.

Because this is a high-tension spring, it is strongly recommended that you upgrade your internal components, particularly the piston, motor, and gears. Installing an SP-150 spring into a stock gearbox can cause premature failure of weaker internal parts.

This Guarder spring features a linear design, meaning the coil spacing is uniform throughout. This typically provides a more consistent FPS output per shot compared to variable-pitch springs.