Very Easy For Use: Press S or M Button to set the second or minute; Press ST/SP button to start/stop the timer;press M button + S button at the same time will RESET the time to 00:00. -Power Supply: 1 x AAA Battery. (For Safety of Shipping, Battery Not Included). -Countup Function: when time on 00:00, press ST/SP button, will count from 00:00 >> 00:01 >> 00:02... -CountDown Function: after set required time, such as 99:59, press ST/SP button, will count from 99:59 >> 99:58 >> 99:57... -When Countdown finished, the Timer will ring "Didididi....Didididi..." to remind you!Press any button to stop the ringing. Material:ABS plastic Size: 2.83*2.56*0.86inch Product colors: blue, pink, white, green. Commodity weight: 0.1lb. Time limit:0- 100min. (Including counting up and counting down) HIGH QUALITY: Four colors are a group, including blue, pink, white, and green. ABS plastic shell, not easy to break and long use time; LCD large screen display, the numbers are clearer ；Plastic buttons, not easy to get dirty, have a strong touch. Safe and non-toxic PC. SCOPE OF APPLICATION: The small timer is powerful. It is used to set lunch break time, study, beauty, sports, meeting, cooking time, etc. It can remind you on time, so you have no worries. SPECIFICATION AND USE: When the timer display is not clear or the sound is weakened, replace the AAA battery. Slide open the battery door, take out the battery, distinguish the positive and negative poles of the battery and put it in, then push the battery door back to its original flavor. GURANTEE FOR YOU:We are dedicated to provide premium product you,If you are not completely satisfied with your purchase or the product is damaged in transit, broken, please contact us promptly, will solve your problems promptly.