This run-walk-run vibrating timer with stopwatch and clock easily sets up your run/walk intervals. Simple setup with dedicated set button. Large display. Low battery indicator. Rugged non-slip case. The timer can be set for any two different intervals from 2 seconds to 99 minutes & offers alarm by beep, vibrate or both. Has clip. AAA battery not included. This item is about the size of a pedometer. Note this item is not water-proof. Some runners use a baggie or purchase the wristband to prevent any moisture problems.