At the first bark, a series of 6 beep sounds is emitted. If another bark is detected within 30 seconds, another beep sound of 2 seconds is emitted together with a stimulation (short or long as selected). Inhibition of any further simulation is dependent on the absence of any barking within the next 30 seconds. Beep-only mode: in this case, only the warning beep sounds will be emitted. The collar is triggered by the vibrations of the dog?s vocal cords. Power: 1 3-V CR123A Lithium battery (supplied). Blue nylon strap - length 76 cm (29.92") / width 25 mm (0.98") ? adjustable for neck sizes from 20 up to 67 cm (7.87" x 26.38").