Innotek Contain-INN-SD2000 Smart Dog Basic Containment System Run-through protection-correction gets progressively stronger as dog approaches boundary. 360 Degree signal coverage/Omni Directional coverage: Prevents your dog from sneaking under&#44; over&#44; If your dog passes through the warning area AND the correction area and keeps on going&#44; the system Anti Linger prevents a dog from lingering in the warning zone area and draining the battery quickly. Constant Alert Operation-This system is always working to protect your pet.