DON"T BUY! Most classes you can use the clicker two, just go buy the clicker two. This one was unreliable, I couldn't tell if it sent my answer, and it won't work with all systems. I used it for ONE class before it stopped working, it would refuse to turn on/off when needed. I had to send it back still on bc it would NOT shut off but when I needed it on in class it would not turn on. Don't be cheap on this one spend the extra little bit to get yourself the clicker two so you can see the answer you sent on the screen, see that it sent, etc. You don't want to have to sit in class and wonder if your clicker is even working when your prof uses them as a participation grade! You will have multiple classes to use it in and if your nice to it maybe you can sell it when your done but even so its worth it to have something reliable.