Detect dangerous leaks in double-walled steel tanks. The presence of liquid in the interstitial space of double-walled tanks triggers an alarm in a TLS-450, TLS-350R, TLS-350, TLS-350J, ILS-350, TLS-300ior TLS-300C monitor. The visual and audible alarm tells you immediately where the problem is so you take quick and efficient action to help prevent safety and environmental issues. The TLS-450, TLS-350R, TLS-350, TLS-350J, ILS-350, TLS-300i or TLS-300C. TLS-250i and ILS-250 can also trigger an on-site alarm for even greater warning capability.