SAFE AND CUSTOMIZABLE: Gives your pets room to play with up to 1/3 of an acre coverage, expandable up to 25 acres with the purchase of additional wires and flags (sold separately) LIGHTWEIGHT RECEIVER COLLAR: Designed for dogs over 8 lb. with neck sizes from 6 to 26 inches ADJUSTABLE, WATERPROOF RECEIVER COLLAR: Features 4 levels of static correction plus tone-only mode for training LOW BATTERY INDICATOR: 1-2 month expected battery life depending on use with easy to install RFA-67 battery CREATE KEEP-OUT AREAS: You can create additional boundaries around areas such as gardens, pools, and swing sets in your yard SURGE PROTECTOR: Protect your In-Ground Fence from surges or spikes U.S.-BASED CUSTOMER CARE: Our pet product experts are here to help you and your pet and are available by phone, email or chat if you have any questions QUALITY PROMISE: PetSafe brand has been a trusted global leader in pet behavior, containment and lifestyle innovations since 1998 to help keep your pet healthy, safe and happy