The best site I've found for ID ing cash coins is http://www.calgarycoin.com/reference/china/chinaid.htm#square hole
The picture of the obverse makes it a little hard to nail down but the "BOO" character on the left on the reverse seems to indicate the Ching dynasty.
Lower image resembles Emperor SHENG TSU
AD 1662-1722
reign title: K'ANG-HSI, AD 1662-1722
"BOO YUWAN" (Board of Works mint). The Manchurian mint name translates to Pao-yuan or "The Source of all Currency".F $2.00 VF $3.50
Scroll down to "S1422"
Darn, beat me to the ID because I was trying to be too fancy! Here's the coin in proper orientaion and a little enhanced, and the CalgaryCoin examples for comparison on the bottom