This timer is good for any classroom activity. It has a built-in alarm and it is easy to use. All you have to do is start the slide show and it automatically starts and finishes. Not to mention it works with any smart board technology. What is special about this timer is that it winds down in real-time. I found this to be useful in class because my students could directly see what time remained for the classroom activity. As educators, we've all used timers in the past and I think it is safe to say that they can be intimidating. I noticed my students felt less challenged by this timer and therefore stayed focused on the task at hand.
I hope that these timers will be successful for you too!