You cannot see the on/off switch wherein the cap will pop right off when twisting the top too far left to turn on/off. This is the downside along with the loud vibrating noise. I was a bit paranoid & tested whether anyone could hear the vibration outside of a closed door...no they cannot! It's a bit hard and much bigger than the advertised picture, check out the dimensions first. Otherwise,it feels alright and will get the job done. I can see it being used alone, but Not something to use with your partner all the time :-(.