SportDOG YardTrainer 100 - The SportDOG Brand YardTrainer 100 is designed for basic obedience training around the house, yard, or park - any situation where your dog is within 100 yards of you. It’s a compact and discrete system packed with premium features at a value price. For dogs 8 pounds or larger with neck sizes 5in - 22in One-dog training only Remote Transmitter charges in 2 hours, lasts 50-70 hours per charge Collar Receiver charges in 2 hours, lasts 20-25 hours per charge