As @PamR said, Chinese Cash Coin. Here's my personal preference for help in ID'ing them. https://www.calgarycoin.com/reference/china/chinaid.htm
Made in huge quantities? Well, so were the originals. After the late 1700s, most Chinese cash coins tend be of very modest value anyway. (Though I’m sure there are rare types and varieties worth more.) Even some 2,000 year old ancient Chinese cash coins are readily available for just a few bucks.
Actually the most common ones are pre 1700s.. Especially the Song issues, Han and Tang issues. Of course very to extremely rare specimens exists..
