The WV711-PLUS’s Vacutec® Smart Pressure® technology produces the densest visible smoke vapor over the unit’s entire range of operating pressure. Smart Pressure® technology software electronics prevent thinning of smoke density that occurs when conventional units are set at high pressure. A denser smoke vapor means it’s easier to see at leak points. It also means a faster UltraTraceUV® dye deposit at the exact location of the leaks, which is essential for high-pressure leak testing! You can’t find all the leaks without it!