Brand new power brake booster - NO CORE Required this is not a rebuilt unit. This is a Brand New Part. This is the A/F/X-body 11" Chrome booster. features the correct triple plating, The clevis rod, plastic check valve, plastic firewall plastic seal and all the details for your concourse car. The check valve is yellow / brown. No Core is required - this is a NEW PART - no a rebuilt unit or a used part.