Will this fit my manual transmission shifter?

This is a universal 50MM ball knob. Most manual shifter shafts accept 50MM adapters, but you may need a threaded insert or adapter ring depending on your shifter's shaft diameter — test-fit or verify your shifter specs before ordering.

Does it need to be painted or prepped?

It ships black and ready to install as-is. If you want a custom finish, light scuffing with fine grit sandpaper will help any coating adhere, but no primer or base coat is required for direct installation.

What's the weight difference compared to a stock knob?

This is a solid, weighted knob versus most OEM plastic units, so you'll feel noticeably more heft in your hand. That's by design — the extra mass smooths out shift engagement and reduces vibration feedback.