The B420 is an effective and simple bark control collar for dogs, with the added benefit of an easy to read screen which allows the user to adjust the settings and functions. The size of this collar unit make it a great choice for smaller dogs. 1. Static, Vibration & Beep functions. Each function can be toggled off and on, and it can be used in 5 modes; Sound only, Vibrate only, Sound and static, Vibrate and static, Sound vibrate & static. 2. USB charging wit the included micro USB cable 3. Adjustable collar size up to 60cm 4. Water resistant - rain and puddles are no problem at all. Please take it off if the dog is going for a swim. 5. You can vary the level of sensitivity through 5 levels. This safeguards against having other nearby noises set the collar off. SEQUENCE OF EVENTS;If using the static function, this collar has the added benefit of being able to choose the sequence of events; Option 1;Bark 1 - warning toneBark 2 - warning tone Bark 3 - warning tone & small static charge Bark 4 - warning tone & increasing static charge Bark 5 - warning tone & increasing static chargethis goes until bark 7, at which time it resets for 1 minute. Option 2 - (for quicker results) Bark 1 - Warning tone, vibration and shock. Dimensions:Length: 5.9cmDepth: 3cmHeight: 3cmWeight: 50gStrap length: 0-54cm Water resistant IPX5