Innotek Basic Contain and Train System Electronic dog-training system keeps pets safely in the yard Up to 5 acres for containment and 150 yards in flat open terrain for training Water-resistant battery-operated receiver; collar fits neck sizes 8 to 21 inches 4 stimulation levels; 2 separate tones; instructional materials included Receiver measures 3-1/2 by 3/4 by 1-3/4 inches; transmitter measures 1-3/4 by 5/8 by 3-1/2 inches; limited lifetime warranty