The Cherne Part #270032 Test Ball Plug is a 3-inch pneumatic plug designed for use in drain-waste-vent systems. Made of durable rubber, this product is suitable for plumbing supplies and is compatible with Cherne brand fittings. The unfinished finish and compact size make it easy to install and provides a reliable seal against leaks. With a weight of 0.45 lbs, this test ball plug is a practical and efficient solution for testing and plugging various plumbing systems.
eBay