This reinforced Spring Guide replace the original Stock Spring Guide of Airsoft AEG
This spring guide with Ball Bearing is designed to minimize the load for the motor caused by the spring tension
Especially important for upgraded AEG to install this
It also makes spring effectively spring back
Backstop is specially equipped with Ball Bearing to prevent Spring Tension build-up during Full Auto Shooting Mode. It greatly reduces the risk of spring breakage
Suitable for Airsoft Model of Tokyo Marui, Classic Army, ICS, G&P, G&G....etc as long as you have the correct gearbox version
FOR GEAR BOX VER.3

As always, upgrading AEG require necessary skill & technique to dissemble the gearbox, consult expertise if needed