Cherne 270040    Test-Ball 4-Inch Plug
Cherne's Single-Size Test-Ball Plugs. Made of natural rubber for excellent expansion and memory. Seals both round and out-of-round pipe. Zinc-plated steel chain and ring handle acts as an anchor to prevent plug from sliding down a line. Fits easily through test tees, sanitary tees, floor drains, and other "tight" situations. Broader expansion range than mechanical plugs.