Turn the timer clockwise until it reaches "55" to prepare it.Then turn counterclockwise to the desired time to start the timer. When the timer ends, it make a loud ring. The alarm ring for 5 seconds at a sound volume of 80~90 db when time reaches zero, Easy to hear in another room. Powered by winding up, no battery is required, Solve the inconvenience of frequent battery change. Completely mechanical - ! So you can carry it anywhere in your home without worrying about it losing power This timer is designed to be small and light. This 60-minute timer is suitable for any place, simple solid color design makes it inconspicuous in any environment; great time management tool for school, homework, office, meeting room, etc.; specially designed for children, Design for parents, teachers, , office workers and students Colour:black+white Material:ABS Size: 6 x 6 x 3.5cm Package Contents: 2 x timer Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.