Ball bearing bushings can increase your AEGs performance. The bearings let your gears spin easier which increases your ROF and reduces heat build up. They are an excellent choice for high speed setups. However be careful because under the stress of a high FPS setup the bearings may fail ruining your gearbox. Even though they can break under a high FPS setup ball bearing bushings made by SHS are more reliable than many alternative brands available and do boost to your AEGs performance.