I love this probe mostly because it is well made and has strong vibrations. The vibrations are in the tip, which was cool because I could point it to the spot that I wanted to feel good. I like how I was able to flex the probe to exactly where I needed. With a little practice I had it hitting my prostrate with no problem. The size was pretty good and the little ridges are OK, but its the vibrating tip and flex that did it for me. Next time I'm going to try it in the shower! It says it's waterproof right?