Dogtra No Bark Collar Small to MediumThe Dogtra YS300 is a bark activated no bark collar made for small to medium sized dogs. The sound recognition sensor uses a microprocessor to distinguish between the dogs bark and the surrounding ambient noise. The YS300 is fully waterproof and comes with a 2 hour rapid charge battery and charger. Package Contents: Bark Collar with collar strap Lithium Polymer Battery Charger Owner's Manual Plastic Dummy Contact Points Features: "Bark Recognition"