Weld-In Manifold Plug - Indmar Exhaust Port Freeze PlugThe Indmar Weld In Manifold Plug is a durable metal plug designed to be welded into an exhaust manifold or similar engine manifold opening to permanently seal an unused port or repair a damaged port. Ideal for inboard marine engine service and custom manifold work, this weld in plug provides a strong, leak resistant seal once properly fitted and welded. Brand Vendor: Indmar Product type: Weld in manifold plug port seal plug Application: Exhaust