These are the products we know which are open source and based on the ADS1299 EEG chip from Texas Instruments OpenBCI HackEEG PiEEG OpenBCI Galea https://www.prnewswire.com/news-releases/openbci-unveils-galea-a-new-platform-that-brings-next-generation-biometrics-to-mixed-reality-301177149.html We often have heard about complaints about products from www.OpenBCI.com that they are expensive. But we are happy now that also OpenBCI products on eBay and Aliexpress are available. …