Designed Specifically for Cats – Features a collar with a safety stretch sectionAdjustable Waterproof Receiver Collar – Fits cats 2.7 kilos and up with neck sizes from 6 – 11 1/2 in4 Levels of Static Stimulation – Emits 4 levels of static stimulation, and also includes a tone only mode for trainingWide Coverage – System covers up to 1,335 square metres with included wire, and can be expanded up to 101,171 square metres with the purchase of additional wire