Aetertek 211D-350W-2 400 Yard 2 Small Dogs Training Anti Bark Collar Can be used as 1 dog or 2 dog training system(need to add extra collar) Vibration, sound and corrective shock can be used separately,Rechargeable Water Resistance receiver collar support small dog weight from 3 lbs to 12 lbs with neck 4" to 17";Manual Dog Anti Bark Range of up to 400 yards (approx. 350 meters) and signal can pass through obstacles, such as walls and fences beep tone function+vibration correction + 10 Levels of progressive shocks