It fits easily on my finger and works great.  It is also useful for keeping time for each lap.  I use it frequently just to ensure I am keeping at  specific pace.  Once you use it and put it back in your bag it will automatically turn off.  Pick it up again and turn it on (push the button) and your results from last time are still available.  I enjoy it, easy to use, excellent price, comfortable....tracks laps, slowest, fastest, average....love it love it love it!!

In a 25 or 50 meter pool, after a bit I tend to loose track of exactly what lap I'm on...

It works, but... I'd rather be able to glance at it and see what lap I'm on, not the time... I can review the times later...

My 2 cents...

Simple to use.  The data that you get back (average time, etc.) is quite useful as you do your workout.

Would be even better if that data were able to be sent (via Bluetooth) to your computer.

I have already recommended it to severa friends.

Using it in a pool and for sprint triathlon training.  Easy to use and very helpful.

Finally! No longer need to count laps!

I train for triathlons and rely on both the lap counter and timer functions to track my training progress.  The Chrono 100 fits securely on my index finger and I have no problems with button operation or reading it as I come out of a turn. I really like the way I can scroll through every lap for individual splits as well as get the average time computed automatically. I have nothing to complain about. Bottom line: this is a simple and well designed unit that I hope will last for years to come. Highly recommended for the serious athlete.