The advanced smoke wizard GLD40 combines pressure and vacuum leak measurement for Evaporative Emission (EVAP) and general purpose leak detection in a compact design. Uses automotive system safe, OEM-approved UltraTraceUV dye smoke solution, the smoke that won’t stink! To find the leak when the smoke is gone or when the leak(s) may be hidden and disassembly is required, use the included combination light to see the dye and pinpoint the exact leak location