Guarder AEG Spring

The SP-170 rating indicates a very high-tension spring, typically designed to push muzzle velocity into the 500+ FPS range depending on your specific air seal and barrel length. Because this is a high-power spring, ensure your gearbox internals, specifically your piston and gears, are upgraded to handle the increased stress.

This spring is designed for Tokyo Marui spec gearboxes, which is the industry standard for most AEGs. It will generally fit Matrix, G&G, and other TM-compatible gearboxes, but always verify that your specific model does not use a proprietary quick-change spring system that requires a different spring length.

Oil-tempered steel is heat-treated to provide superior elasticity and resistance to 'spring fatigue.' This means the spring maintains its tension and FPS consistency over thousands of cycles, whereas cheaper, non-tempered springs may lose power or deform more quickly under high-stress builds.

Yes, installing an SP-170 spring puts significant strain on your gearbox. You should absolutely pair this with a high-torque motor, reinforced steel gears, and a piston with a full metal tooth rack to prevent premature failure of your internal components.

While the physical dimensions are a drop-in fit for standard gearboxes, the installation requires you to fully disassemble your gearbox. If you are comfortable opening your gearbox, the spring itself installs easily, but be prepared for the mechanical tuning required to ensure the rest of your system can handle the power increase.