High Tech Pet Humane Contain HC-8000 Electronic Dog Fence Ultra System and PT-2 Pro Trainer Plus Sonic Cat & Dog Trainer Combo Includes Humane Contain HC-8000 electronic fence system and Pro Trainer Plus PT-2 sonic cat and dog trainer Uses proprietary technology to automatically adjust stimulus intensity based on distance from boundary, keeping pet contained without overstimulation Progressive audible tones reinforce shock stimulus resulting in an even quicker, easier training process Pro Trainer is a hand-held device that trains dogs and cats with sound, not shock stimulus; no collar is required Pro Trainer features 3 obedience tones plus a NO tone with LED command indicators