Smoke Fluid Systems from Superior Signal Company are used to find faults and sources of surface water inflow in collections systems. Smoke fluid is both high quality and economically priced. Blowers are engineered for smoke testing, using a double-insulated heating chamber with stainless steel injector to maximize dry smoke output and produce quality liquid-based smoke. Blowers can be configured to work with Superior Smoke Candles. 800/945-8378; www.superiorsignal.com.