Precision machined from solid 6061 aluminum billet, the Magnus Pro Hop-Up chamber features a true vertical TDC (Top-Dead-Center) movement. This means regardless of your hop-up setting, the pressure point remains in the same position for consistent results. The O-ring fitted grub screw directly under the chamber unit offers positive & intuitive adjustments which can be easily accessed by removing the slide assembly. Enclosed elevating ring design ensures precise movement without the possibility of misalignment.