Our take: This JBU M100 Airsoft upgrade spring is made for most-all airsoft metal gearbox AEGs. Constructed of oil-temper steel wire with an irregular pitch, it is one of the best ways to adjust the FPS output of your metal gearbox AEG. High quality, low price tag. This is a perfect spring for any AEG that will be used at CQB fields, which normally set an FPS limit of 350 FPS. FPS rating: 320-340 FPS
Disclaimer: Any and all airsoft upgrade parts purchased from Airsoft Megastore will be used/installed at owner's discretion. We are not responsible for any damage that may occur. For best results, please have a professional airsoft Tech install all upgrade components at a certified professional airsoft technician/shop.