Chheung (Chhing), the hand cymbals from the Pin Peat orchestra.
There are two main sounds produced with the Chhing. The "chop" sound is produced on strong beats by bringing the two Chhing squarely together, while the "cheung" sound is produced om weaker beats by hitting the Chhing together obliquely with a slashing motion – as on the picture.
Ref. Cambodian Music by Keo Narom, p 236