How to use: Press S to set the seconds display position, press M to set the minutes display position, press START/STOP to start or stop and at the same time press MS- to reset the display to zero. When the set time counts down to zero seconds, an alarm will occur. Functions: Countdown function, up to 99 minutes 59 seconds, automatically returns to the set countdown time when the countdown is complete; counting function, press M and S simultaneously to reset, then press START to start counting. Product attributes: External dimensions: 8..2*7.2 cm,, uses regular AAA batteries (this product does not have batteries, you need to buy them yourself). Small and portable: with magnet and stand, free hanging hole on the back; can be attached to a metal surface, placed on a table or hung; the clip has a foldable hanging hole on top, suitable for hanging on a peg Large screen: clear display with large numbers and a three-button design for easy operation and setting. The product has a back clip on the back to clip onto a belt.