The FINIS Tempo Trainer Pro combines convenience and portability, using beeps to guide your stroke rate and maintain your rhythm during swimming sessions. Features Multi-Sport: Applicable for swimming, biking, running and more Audible Beep: Loud enough to hear in and out of the water Sync Button: Synchronize the device to a pace clock or stopwatch Adjustable: Tempo can be adjusted by 1/100 of a second Waterproof and floats in the water to avoid being lost External clip included to keep it in place on the swim cap 3 different modes: - Mode 1: Single beep in strokes per sec (0.02 seconds to 99.99 seconds). - Mode 2: Triple beep in strokes per sec (1 second to 9:59 minutes). - Mode 3: Single beep in strokes per minute. Sync button lets you synchronize the trainer to a pace clock or stopwatch. Small, convenient size makes it easy to place under swim cap Replaceable battery Auto shut off feature Purchased for $48 new, asking $20 Missing clip, needs new CR1620 3V battery