6 KEYS in this water meter system：
" MENU " - press MENU key to different setting mode ; confirm the setting.
" SET " - to set the flow parameters.
" + " - setting number + ; hold 3 sec to turn Chinese / English ( in the stop working mode ).
" - " - setting number -- ; hold 3 sec to turn Liter / Gallon (in the stop working mode ).
" ON/OFF " - press on/off to turn filling mode start / stop.
" RESET " - reset the setting flow / K value or turn to zero.
K value of sensor model YF-S402B : 32*Q