Cherne® Single-Size Test-Ball® Plugs are expandable rubber test plugs designed to test drain, vent and waste systems in every type of pipe. Utilizing a standard tire air fitting for easy connections, its inflatable design can be inserted through a test tee to seal out-of-round pipe and hard-to-access openings. These plumbing test plugs are available in a variety of nominal sizes to accommodate your DWV testing needs. Cherne Industries is a global leader in pipe plug, blocking and testing.