Enhance your AEG with our BCI G&P Stoner 63 TDC-7 Hop Up Assembly. Complete with the arm pin, 2 hop up different size nubs and wheel O-ring, it's ready to install and provides improved performance and reliability with its top dead center adjustment. Compatible with after-market AEG barrels and featuring our latest revision—June 2023—you can trust our hop up assembly for a seamless install.