This is such an improvement from CStimer and the price is so low!
Its also more precise if that's what you like. The sensors have never failed and the buttons don't get stuck. Here's some tips though. There's a plastic film over the timer, peel that off it makes the buttons stick down. The build is a little flimsy, so when you are **** the battery lid back on make sure you press down between the bottom and the top or the **** won't go in.