SportDOG designed the YardTrainer 105S Electronic Dog Trainer for Stubborn Dogs to meet your training needs with even the most difficult of dogs. With eight intensity levels, you can find the perfect one for your pet and apply more stimulation as required. Safe for your dog, the system includes both a collar and transmitter for easy training from up to 100 yds. away. Product includes Basic Training Instruction with Pro-Trainer Charlie Jurney to help you and your dog through the training process safely and efficiently. A waterproof collar receiver and water-resistant transmitter make this unit great for any weather conditions or terrains. Remote transmitter has 100 yd. range. Not recommended for dogs under 8 lbs. Remote transmitter and collar receiver each require two 3V CR2032 batteries for up to six months of use (batteries included).