Do I need to match this hose to my existing fuel line, or can I just buy 1/2 inch?

Measure your current hose diameter—don't estimate. 1/2 inch is common, but some vehicles run 3/8 inch or larger. Check before ordering to avoid a mismatch.

What fittings or clamps do I need to use this hose?

This is hose only. You'll need to source compression fittings or barbed adapters that match your fuel system layout, plus stainless steel hose clamps. Bring your old line to a parts counter to confirm fitting size.

Can I use this for a fuel return line, or just the main feed?

NBR handles both fuel feed and return—it's fuel-system grade. Check your vehicle's fuel system diagram to confirm which sections need replacement and plan your cuts accordingly.