Oatey 041386 Cherne 8-Inch 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. Made of natural rubber for excellent expansion and memory.Seals both round and out-of-round pipe Fits easily through test tees, sanitary tees, floor drains and other "tight" situations Broader expansion range than mechanical plugs. Zinc-plated steel chain and ring handle acts as an anchor to prevent plug from sliding down a line