A 1/2″ NPT socket plug for blanking large tapered pipe ports. Ports of this size appear on sumps, oil pans, tank and swirl pot bosses, large filter and cooler housings and industrial-style adapter blocks, and this plug closes them off cleanly when the outlet is not in use. The internal hex drive sits flush in the boss rather than standing proud, which helps where ground clearance or nearby components are a concern. NPT seals on the taper, so use thread sealant or PTFE tape and tighten finger tight plus one to two wrench turns rather than winding it in hard.