Cherne 270188 Clean-Out 4 Mechanic Gripper Plug Made with glass-reinforced ABS plastic Black color blends well with cast-iron pipe Stainless steel hardware prevents corrosion NPT sizes, including hard to find 3 Natural rubber threaded O-ring for positive seal Guaranteed to seal most damaged threads Patented threaded O-ring ensures airtight seal Stainless steel hardware prevents corrosion Guaranteed to seal all damaged threads Made with glass-reinforced ABS plastic and natural rubber O-ring Made with glass-reinforced ABS plastic Black color blends well with cast-iron pipe Stainless steel hardware NPT sizes (2, 3, 3.5, 4) Natural rubber threaded o-ring for positive seal