The Leak Type K Gauge is a reliable, vertical type leak monitor used for detecting leaks in the annular/interstitial space of a double wall above ground containment tank (AST's). Its simple mechanical design promotes durability, minimal upkeep, quick installation, and easy/inexpensive repairs. This interstitial monitor is custom made in house to fit your tank. Features Aluminum Rods HDPE plastic floats Aluminum bushing Type - K Bushing Size - 2 in