Currently. P300-BCIs are mostly used for spelling tasks. where the number of commands is equal to the number of stimuli that evoke event-related potentials (ERPs). Increasing this number slows down the BCI operation because each stimulus has to be presented several times for better classification. https://www.bekindtopets.com/great-pick-Nobivac-Feline-1-HCPCh-special-find/