Specially designed ear clips typically used with Lexicor style Electro-cap with ear leads. 3 1/2 inch DIN Style EEG ear clips. For Lexicor style Electro-caps with ear leads. Standard 1.5mm DIN socket. This short ear lead plugs into the DIN socket on the cap. These are the "old style" lead with a soft rubber backing.
This design allows you to connect the E5-9SDROPS ear clips right into the Electro-cap. These are the old style clips. New style can be found here.