Hanna (HI7071) Electrolyte Solution, 3.5M KCl + AgCl 4 x 30 mL bottlesHanna Instruments Hanna HI7071 Electrolyte Solution 3. 5M KCl + AgCl refill solution for maintaining optimal electrode performance in refillable pH and ORP probes 4 x 30 mL Bottles FDA Compliant 3. 5M Potassium Chloride WHY IT WORKS Precision measurement depends on proper electrode maintenance Maintains Electrode Junction The 3. 5M potassium chloride concentration with silver chloride ensures consistent ion flow through the reference junction,