When your dog barks, the collar emits a warning beep followed by a harmless, yet effective, static correction. Set the level for your dog or let the collar take over and automatically determine the appropriate level. Simple and easy to use. 4 operating modes: beep only. beep + light static correction. beep + strong static correction. beep + automatically adjusting static correction. On/off mode and all the different modes selectable through the magnetic key. Bark detection by contact points (detects the vibrations of your dog’s barking). Battery level indicator (indicator light). Bark detection sensitivity adjustable by potentiometer. Specifications: Weight: 3.1 oz. (case + battery). Dimensions: 2.5″ x 1.25″ x 1.4″. Power: rechargeable 3,6 volt Ni-MH battery. Adjustable nylon strap on neck sizes from 6.6″ to 21″.