We have bought a batch of these stopwatches to use for Official Timing on our Autosolo events. These are competitive Motor Sport event timed to 1/10th second. Timing devices do not have to be calibrated and are usually operated by club members who are not specialist timekeepers. This model is ideal because it is a nice size that fits in the hand, well designed operating buttons, large display and water resistant, as these events are outdoors and run all year round. Overall, a very good value, well designed and manufactured timepiece.