Stelth Model SRE-013-CPY
Copper-Copper Sulfate (Cu-CuSO₄)
permanent portable with wide sensing area for soil or concrete surfaces in chloride free conditions

Stelth Model SRE-014-SPB
Silver-Silver Chloride (Ag-AgCl)
permanent portable with wide sensing area for soil or concrete surfaces in chloride conditions

Stelth Model SRE-015-ZPR
Zinc-Zinc Sulfate (Zn-ZnSO₄)
permanent portable with wide sensing area for soil or concrete surfaces in chloride free conditions