Extra Flat Electrode, 1mm thick Ag-AgCl without housing. Can be used indefinitely with some care. Lead wire available in 8 colors (white, green, brown, red, black, blue, orange & yellow) up to 60” (150cm). Standard lead wires are PVC insulated multi-strand copper with internal Tinsel for additional strength. Easily cold sterilized and used for a variety of applications such as EEG, EMG, EOG, etc.