Hi, I agree with Richard. When you press the switch, it "sends" a lot of pulses (because of machanic) and you have to make hardware or software filter to eliminate pulses shorter than... it depends on your application. Sometimes you can buy a very good switch and it don't need the filter, sometimes not. But it is VERY GOOD solution to make the software or hardware filter EVERYTIME you are using switches. It is absoulutly neccesary!