The Leakage Sensor for Double-Walled TanksVISY-Reed Interstitial sensors detect the presence of liquids in the interstices of double-walled tanks. They function as alarm systems and monitor the level of the liquid. VISY-Reed Interstitial is available as a "Dry" variant for dry interstices and a "Wet" variant for interstices filled with liquids. Sturdy and stable design Housing made of brass, floater made of stainless steel Response threshold at about 30 mm