Cherne's Original Single Size and Multi-Size Test Ball Plugs are our most economical pneumatic plugs for blocking flow to do maintenance in sanitary and storm sewer systems. These plugs may also be used as a back plug for sewer air tests. All of the single-size and multi-size Test Ball plugs have eyebolts for attaching a rope or clevis for lifting and lowering the plug. And each plug also has a removable Schrader valve for easy replacement or substitution with a quick disconnect fitting. Made from natural rubber, these plugs are tough, tear-resistant and will work on any type of pipe, including out-of-round pipe.