Nanatsu Kankaku (Literally meaning "Seven senses") is a technique created by Tōsen when he was trying to find new ways of using his devil fruit, Tosen discovered that he can using his devil fruit's ability combined with Life Return to detach parts of his body and break them down to a molecular level and then have them fly around him in the form of a field, if anything comes in contact with these detached moleculs, Tosen will sense it.