We are very pleased to be receiving our first batch of 2.5mm jack electrodes. While the industry standard for EEG electrodes is a din type connector, for the PiNaps and TeeNaps platforms, we decided this would result in excess bulk preventing our goal of small form factor. Further, the jack connector in TR or TRS (Tip Ring / Tip Ring Sleeve) formats, allow us to integrate shielding and multiple lines into single, pluggable electrodes. We have been testing and working in collaboration with our manufacturers to design these 2.5mm jack electrodes for a little while and we are just getting our first stock in now.
These are approximately 30cm in length, allow for easy attachment and feature integrated shielding. These are intended largely for on head applications and we are considering different length variations in future (based on demand). We are planning on producing extensions as the next addition to this range, for applications where the device is not head mounted.
Of course you can always just make you own electrodes, but more on that later.