It is an autoclavable Ag/AgCl reference electrode equipped with ceramic frit sealed using PTFE into the PEEK body. All materials used to fabricate this electrode are suitable for hydrothermal processes. However, even PEEK and PTFE can withstand a limited number of autoclave cycles before crazing. The number of steam autoclave cycles that an autoclavable Ag/AgCl will be able to withstand before deteriorating depends mainly on the autoclave temperature, cycle time and Ph of the solution. 

Application note
This electrode is suitable for an aqueous environment under hydrothermal conditions. The electrode should be refilled with an electrolyte (typically 3M KCl) before each use. The electrode can be stored dry or immersed in an electrolyte (3M KCl or a buffer solution).