Q-See QSNDVR16M User Manual page 66

Brief introduction of buttons:
: Play : Pause
: Stop : Fast backward
: Step backward : Step forward
: Fast forward
: Verify if the record has been changed or not : Volume control
: Snap shot : Number button
/ / 1-channel/4-channel/9-channel/16-channel mode
/
You can use number button to choose the channel which you want to see.
Page 68