The name of the coin is "Kanei tsuho"(coin of kanei) (kanei is the name of era in Edo period), on which characters of "permanent use" and hallmark of "chin"(珍) between the characters were inscribed at the back..
銭文は「寳永通寳」であり、背（裏面）には「永久世用」と鋳込まれ、その字間に「珍」の極印が打たれている。