SmartBall® is an innovative free-swimming inspection technology designed to operate in a live pipeline. It is a free-swimming foam ball with an instrument-filled aluminum alloy core capable of detecting and locating very small leaks, gas pockets and structural defects in pipelines. There is no apparatus noise, so it can detect very small leaks. Typical location accuracy within 10 ft. (3 m) Small size allows it to pass through inline valves, reducers and other appurtenances. http://www.puretechltd.com/products/smartball/smartball_leak_detection.shtml