Cherne 270138 Clean-Out Gripper 3-1/2-Inch Plug Seals with 4-Inch Threaded Opening Ideal for use in hub fittings and in bell-end pipe. Pressure rated for conducting DWV tests. Yellow color enhances visibility in pipe. Made with glass-reinforced ABS plastic and natural rubber O-ring. 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. Size 3.5 in 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