Safe and Customisable – Gives your pets room to play with up to 1,335 square metres coverage, expandable up to 101,171 square metres with the purchase of additional wires and flags (sold separately)Lightweight Receiver Collar – Designed for dogs over 3.6 kilos with neck sizes from 6 to 26 inchesAdjustable, Waterproof Receiver Collar – Features 4 levels of static stimulation plus tone-only mode for trainingLow Battery Indicator – 1-2 month expected battery life depending on use with easy to install RFA-67 battery