These large sensors are used primarily for active sensor placements on the head. They are pre-gelled and made of soft cloth for comfort but do require 10-20 conductive paste when placed in the hair. These silver-silver chloride sensors are 1-3/8" X 7/8". For single-channel placements, this pack will typically last for about 30 training sessions. For two-channel placements, this pack will last for about 15 training sessions.
