Three parts, one problem: the slack between your hand and the gearbox.
On a high-mileage manual E46 that slack has three sources — the flex in the factory shift carrier, the rocking play in the single-shear selector rod joints, and the movement of the transmission on soft rubber mounts. Fixing one moves the limit to the next, which is why these are built as a set rather than three separate upgrades.
Pick whichever you need below. Take any two and 10% comes off automatically at checkout.