Cap connectors

Brainvision/EASYCAP

Electrode caps from these companies use Pak50 connectors (common connector type from 3M).  These are characterized by having two parallel rows of pins.  Depending on what cap type you select there will be, generally, 40 or 50 pins per connector that correspond to 32 channels.  This means a 64 channel cap will have two connectors, 128 channel will have four connectors, etc.