Not sure how accurate it is, but is easy to use.

I am not sure why others are having a lot of trouble with this item, as it is pretty easy to use. All you need to do is mark off the distance on the ground and set the ball accordingly. I believe the distance settings are 40', 43', and 46'. It times the pitch from release to point of impact with mitt (or ground but we try to avoid that as wrong readings result.) It works for us and this is our second year using the same ball. So far no battery problems. Can you change the battery? Not sure, don't see how you could without ruining/destroying the ball. Is the speed reading accurate? Not sure either, as we have nothing else to compare to, but I would say it's probably pretty close. We really use it to compare pitch speeds to each other which is a helpful training tool, rather than to try to use it to brag. For us it is worth it because we can see progress as it develops, which is an encouragement.

My daughter is a pitcher and she does have a pitching coach who has one of those expensive radar guns to clock her pitches; however, we really wanted a tool we could use at home to monitor her performance. Not wanting to spend $$$ on a radar gun, I ordered this and figured I couldn't go too far wrong for the price.

Once we received it, we took it to her next pitching lesson so we could compare it to the radar gun. The reported speed on this ball was within 1mph of the gun (consistently above by 1mph). This was well worth the price. If the one we received is representative of the general quality of this sensor, I would recommend to anyone looking for an affordable way to clock pitching/throwing speed.

Bought it for my 11 year old granddaughter. She's works on her speed in softball. This will make her a faster pitcher when she she's the numbers. She's a great pitcher and any thing to help her.

I just received the ball a few hours ago. My daughter and some other girls tried it several times. At first I thought I had bought a piece of junk. To pitch the ball, you must use a softball pitching grip with fingers on the seams and thumb at the start button. If your entire hand is not around the ball it will not work correctly. Set the distance while palming the ball. Next grip it like I mentioned above with your thumb lightly pressing on the start button. The dashed lines should stay lit up. It will measure the time from when you let go of the ball until when the glove catches it. I would have rated it 5 stars if the directions would have been better. If you set your distance at 40 feet, but are actually pitching from 35 feet all you need to do is multiply the reading by 0.875 to get the true speed.